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Full text of "Proceedings of the American Society of Agronomy"

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THE UNIVERSITY 
OF ILLINOIS 
LIBRARY 

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AMR 

v.7cop3 



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This book has b^e^^JP^.^Ii]^!?^^ 
and is available OWLlMt. 



Digitized by the Internet Archive 
in 2013 



http://archive.org/details/proceedingsofanne7191anner 



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JOURNAL 

OF THK 

AMERICAN SOCIETY 
OF AGRONOMY 



VOLUME 7 



1915 



PUBLISHED BY THE SOCIETY 



Press of 
The new era Printing Company 
lancaster. pa. 



DATES OF ISSUE. 

Pages 1-48, March 16, 191 5. 
Pages 49-96, April 29, 191 5. 
Pages 97-144, June 17, 191 5. 
Pages 145-192, July 31, I9i5- 
Pages 193-256, October 20, 191 5. 
Pages 257-320, December i, 191 5. 



iii 



, 7 UNlVtRSITY OF ILUNUli 

^' ' AGRICULTURE UBR^RY 

Cop. 3 

CONTENTS 

No. I. JANUARY-FEBRUARY. 

Piper, Chaklks V., and Bokt, Katherine S. — The Early Agricultural His- 
tory of Timothy i 

Lynde, C. J., and Dupre^ J. V. — On Osmosis in Soils (Fig. i)' 15 

Warburton, C. W. — Grain Crop Mixtures (Fig. 2) 20 

Briefer Articles. 

^ Montgomery, E. G. — On Naming Varieties 29 

, FRAPS, G. S. — Moisture Relations of Texas Soils 31 

Fraps, G. S. — Relation of Chemical Composition to Soil Fertility .... 33 

McClelland, C. K. — The Production of Corn in Hawaii 36 

Agronomic Affairs. 

Foreword 39 

The Problem of Varietal Names 40 

Membership Changes 41 

Notes and News 42 

Coming Events 47 

Local Sections 48 

No. 2. MARCH-APRIL. 

Klein, M. A. — Studies in the Drying of Soils (Fig. 3) 49 

Carleton, Mark Alfred. — Problems of the Wheat Crop 78 

Ellett, W. B., and Carrier, Lyman. — The Effect of Frequent Clipping 

on Total Yield and Composition of Grasses 85 

Agronomic Affairs. 

Meetings of the Society 88 

Brief Articles for Publication 89 

Annual Dues of Members 89 

Membership Changes 89 

New Books ■ 91 

Notes and News 92 

Coming Events 95 

Local Sections 96 

No. 3. MAY-JUNE. 

Brown, P. E., and Kellogg, E. H. — Sulfur and Permanent Soil Fertility 

in Iowa 97 

Piper, Charles V. — The Prototype of the Cultivated Sorghums 109 

Helmick, B. C. — A Method for Testing the Breaking Strength of Straw 

(Fig. 4 and PI. I., Fig. i) 118 

Love, H. H. — Methods of Determining Weights per Bushel (PI. I, Fig. 2) 121 
Coffey, G. N., and Tuttle, H. Foley. — Pot Tests with Fertilizers Com- 
pared with Field Trials (Fig. 5) 129 

V 



5^7041 



vi CONTENTS. 

VooRHEES, John H. — Variations in Soy Bean Inoculation 139 

Agronomic Affairs. 

Meetings of the Society 141 

Membership Changes 141 

Notes and News 143 

No. 4. JULY-AUGUST. 

Davidson, Jehiel. — A Comparative Study of the Effect of Cumarin and 

Vanillin on Wheat Grown in Soil, Sand and Water Cultures 145 

Lacy, Mary G.— Seed Values of Maize Kernels : Butts, Middles and Tips . 159 
Arny, a. C, and Thatcher, R. W.— The Effect of Different Methods of 
Inoculation on the Yield and Protein Content of Alfalfa and Sweet 

Clover 172 

Etheridge, W. C— Varietal Names of Oats 186 

Agronomic Affairs. 

Program for the Berkeley Meeting 189 

Membership Changes 190 

Notes and News 191 

Coming Events 192 

No. 5. SEPTEMBER-OCTOBER. 

Wright, R. Claude. — The Influence of Certain Organic Materials upon 

the Transformation of Soil Nitrogen (Figs. 6--12) 193 

Leighty, Clyde E. — Natural Wheat-Rye Hybrids (PI. II and III) 209 

Brown, P. E., and Johnson, H. W. — The Effect of Grinding the Soil on Its 

Reaction as Determined by the Veitch Method 216 

Davidson, Jehiel. — A Comparative Study of the Effect of Cumarin and 
Vanillin on Wheat Grown in Soil, Sand and Water Cultures (Con- 
clusion) 221 

NoYES, H. A. — Soil Sampling for Bacteriological Analysis (Fig. 13 and PI. 

IV, Fig. I) 239 

McCall, a. G.— a New Method for the Study of Plant Nutrients in Sand 

Cultures (PI. IV, Fig. 2) 249 

Agronomic Affairs. 

Notes and News 252 

Membership Changes 255 

Local Sections • • • 256 

Coming Events 256 

No. 6. NOVEMBER-DECEMBER. 

Thorne, Charles E.— The Work of the American Agronomist (Presi- 
dential Address) 257 

Wolfe, T. K.— Further Evidence of the Immediate Effect of Crossing 

Varieties of Corn on the Size of Seed Produced 265 

Thatcher, R. W.— Progressive Development of the Wheat Kernel— II ... 273 

Lynde, C. J., and Dupre, J. V.— On Osmosis in Soils (Figs. 14, 15) 283 

Agronomic Affairs. 

Notes and News 293 



CONTKNTS. vii 

Report of the Secretary for i(>i5 295 

Funds Collected 2(;s 

Meetings _'</, 

Local Sections 2(/j 

Membership 296 

Address List of Members • '. . 298 

Journal and Proceedings 308 

Minutes of the Annual Meeting 309 

Report of the Treasurer 311 

Reports of Committees 312 

Executive 312 

Soil Classification and Mapping 313 

Agronomic Terminology 314 

Varietal Nomenclature 314 

Index 317 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. 7. January-February, 1915. No. i. 



THE EARLY AGRICULTURAL HISTORY OF TIMOTHY.^ 

Charles V. Piper and Katherine S. Bort. 

Offick of Forage Crop Investigations, U. S. Department of Agriculture, 

Washington, D. C. 

Timothy is by far the most important hay grass cultivated in 
America and for a century at least has occupied this economic posi- 
tion. A peculiar interest attaches to this grass because it was first 
cultivated in this country. Owing perhaps to this fact nearly every 
American writer who has discussed the crop has given an account 
of its early history. These published narratives show, however, many 
discrepancies in details, as may be seen in the extracts here quoted, 

Wiggins, 2 writing in 1840, gives the history as follows: 

" Timothy is a well-known favourite and native grass of the middle and 
northern states ; it also flourishes well in the Carolinas, whence it was introduced 
into England by Timothy Hudson, about the year 1780. It is known in English 
practice as the meadow cat's-tail or timothy grass. In New England it is 
called herd's grass ; while in other sections of the United States it is known as 
the herd's of the north, or red-top timothy." 

Flint,^ a quarter of a century later, has the following less inaccurate 
account : 

" The name of Timothy, by which it is more generally known over the coun- 
try, was obtained from Timothy Hanson, who is said to have cultivated it 
extensively, and to have taken the seed from New York to Carolina. Its 

1 Received for publication Jan. 7, 1915. 

2 Wiggins, F, S., American Farmers Instructor, p. 228. 1840. 
^ Flint, Charles L., Grasses and Forage Plants, p. 34. 1864. 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



culture was, according to some accounts, introduced into England, from Vir- 
ginia by Peter Wynche, about the years 1760 or 1761. 

" It is frequently called Herd's grass in New England and New York, and 
this was the original name under which it was cultivated ; it was derived from 
a man of that name, who, according to Jared Eliot, found it growing wild in a 
swamp in Piscataqua, N. H., more than a century and a half ago, and began 
to cultivate it." 

Vasey^ in 1884 makes this statement about the matter: 

" This grass, as known in cultivation, is supposed to have been introduced 
from Europe, but it is undoubtedly indigenous in the mountain regions of New 
England, New York, and the Rocky Mountains. It is said that about the year 
1711 a Mr. Herd found this grass in a swamp in New Hampshire and cultivated 
it. From him it took the name of Herd's grass. About the year 1720 it was 
brought to Maryland by Timothy Hanson and received the name of Timothy 
grass." 

In the works of more recent writers there is no greater concordance 
as to the details of its early history, as the following quotations make 
manifest : 

" It was called Timothy, after Timothy Hanson, who, in the middle of last 
century, cultivated it first in Carolina, and later, in Virginia. In 1760, Peter 
Wynch, President of the Agricultural Society of England, obtained the seed 
of this species, along with that of several other grasses, from North America. 
In 1763, it was recommended in the Annual Register and the Museum Rusticum 
as deserving of more extensive cultivation. Soon after it was brought into 
notice on the continent by the Agricultural Societies there." — Stebler & Schroter.^ 

" The first name comes from Timothy Hanson, of Maryland, who introduced 
the grass from England in about 1720. The next name comes from a man by 
the name of Herd who found it growing in New Hampshire and began its 
cultivation. In 1760 or 1761 Peter Wynch took seeds of it from Virginia to 
England."— W. J. Beal.s 

"It was introduced into Maryland about 1720, from Europe, where it is 
native, by Timothy Hanson, and hence called Timothy. The other name is 
said to come from a man by the name of Herd who found it growing in New 
Hampshire and began its cultivation." — A, S. Hitchcock."^ 

" The name Timothy comes from Timothy Hanson or Hanso, of Maryland, 
who is said to have introduced the seed from England in 1720 and who is 
responsible for its distribution through Virginia and Carolina. The name 
Herd's grass is from John Herd, who is said to have found it growing wild 
in a swamp in New Hampshire as early as 1700 and began its cultivation, result- 
ing in its distribution through New England and New York." — T. F. Hunt.^ 

* Vasey, George, U. S. Dept. Agric, Misc. Report No. 32, p. 63. 1884. 
^ Stebler and Schroter, The Best Forage Plants, p. 52. 1889. 

* Beal, W. J., Grasses of North America, i : 103. 1896. 

Hitchcock, A. S., in Bailey's Cyclopedia of American Agriculture, 3 : 1305. 
1903. 

^ Hunt, T. F., Forage and Fiber Crops in America, p. 52. 1907. 



VIVER AND IIOIM': .\( iK I ( ' I ' I . T I ' U A I . IIISIOUV Ol- 11 MOTHS' 



3 



While these accounts (hiTer considerahlx in detail, they are similar 
enough to suggest a common source. ( )ne of these sources is certainly 
the account by jared I^liot," written in 1749. I'his indeed is referred 
to by h'lint. I^liot writes as follows: 

** There arc two sorts of grass which arc natives of the country, which I 
would recommend; these are Herd Crass (known in Pennsylvania hy the name 
of Timothy-grass) the other is Fowl Meadow, sometimes called Duck Grass, 
and sometimes Swanit^-zmrc grass. It is said that Herd grass was first found 
in a swamp in Piscataqiia hy one Herd, who propagated the same." 

Eliot's statement in this quotation, " known in Pennsylvania by the 
name of Timothy-grass," was probably based on information he re- 
ceived in a letter from Benjamin Franklin, dated July 16, 1747, to 
whom he had sent herd-grass seed. Franklin says : 

" You made some mistake when you intended to favor me with some of the 
new valuable grass seed (I think you called it herd-seed), for what you gave 
me is grown up and proves mere timothy; so I suppose you took it out of a 
wrong paper or parcel." 

The letter of Franklin is still preserved in the Library of Yale 
University. It is published by Bigelow^*^ and by Smyth. 

Eliot also mentions the grass in his first essay (1. c, p. 6), written 
in 1747. 

" I then proceeded to sow Grass seed, such as red Clover, foul Meadow-grass, 
English spear grass and Herd grass." 

And again in his third essay (1. c, p. 58), 

"In reading Mr. Ellis, I find by him that in England they have got Herd 
Grass seed from this country, and set a value upon it." 

. Eliot's reference to Ellis doubtless pertains to William Ellis, a pro- 
lific contemporary English writer on agricultural subjects. Apparently 
the only mention by Ellis^^ and what might well be the basis of Eliot's 

9 Eliot, Jared, Essays upon Field-Husbandry in New England, p. 57. Boston, 
1760. (This work comprises six essays which, according to the Library of 
Congress records, were first printed separately in New London and New York 
as follows: First essay, written in 1747, printed in 1748; second, printed 1749; 
third, 1751 ; fourth, 1753; fifth, 1754; sixth, 1759. The combined essays were 
published in one volume in 1760. Rev. Jared Eliot, rector of Killingworth, 
Conn., was a farmer of thirty years' experience, and his essays on the agri- 
culture of New England are among the most important of his day. He was 
a graduate of Yale, a fellow of the Royal Society, and the teacher of Samuel 
Johnson, the first president of Kings College.) 

10 Bigelow, John, Letters and Works of Benjamin Franklin, 2: 77. 1887. 

11 Smyth, Albert Henry, Life and Writings of Benjamin Franklin, 2: 310. 
1905. 

12 Ellis, William, Agriculture Improv'd : or the Practice of Husbandry Dis- 
play'd, I : 106. 1746. 



4 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



note is the following letter of Ellis to published in 1746. 

" I have had some Grass seed from in America, called St. Timothy- 

seed ; which is an artificial Grass, that will grow six Feet high, and will mow 
four or five times in a Summer, in good Ground; I have sowed it in my Garden, 
and hope to have a good crop of Seed from it: If I have, as I hope, from its 
being come up very green, I will send you some, if you care for it. A Friend 
of mine try'd it last Year, with very great Success." 

No other mention of timothy has been found in a thorough search 
through Ellis' writings. 

Eliot says, as quoted above, that herd grass was first found in a 
swamp in Piscataqua by a man named Herd. That there was a family 
by the name of Herd settled near the mouth of the Piscataqua is con- 
firmed by the following letter, received from the secretary of the New 
Hampshire Historical Society : 

"In the first place the first settlement in New Hampshire was made about 
1623 when Mr. David Thompson came to the mouth of the Piscataqua River 
to make a settlement. This is on the sea coast in what is now Rockingham 
County and the towns of Dover and Portsmouth were among the earliest 
towns; consequently I have looked among the records of these, and in Ports- 
mouth about 1653 firid that some land was granted ' upon the neck of land by 
Winacont River Commonly called John Heards necke ' ; this was in what was 
called the 'Grant of Pescataway ' or 'Piscataqua Patent,' names taken from 
the river, which is variously spelled. I also find the record of the marriage 
of Joseph Heard of Dover and Rebecca Richards, on August 9, 1722. Evi- 
dently the Heard family was prominent in Dover and Portsmouth, for in the 
Wentworth genealogy I find a genealogy of some of the Heards. One Tris- 
tram Heard was killed by the Indians at Dover in 1623 ; of his descendants, a 
Joseph Heard was born in 1692 and a John born 1700 and may have been those 
mentioned above. The family was connected with the Wentworth family by 
marriage. Though I can find no record of a person by the name having culti- 
vated timothy, the fact that there were so many of the name living about that 
date in that section known as the Piscataqua Patent leads me to believe there 
is some truth to the statement that Mr. Heard cultivated it in New Hampshire." 
(Letter to C. V. Piper, Aug. 20, 1908.) 

In regard to the name timothy, it is so far as the literary evidence 
goes as old as the name herd grass, and apparently both were well 
known in 1747, the former being used in Pennsylvania and the latter 
in Massachusetts. The name timothy has commonly been stated to be 
derived from one Timothy Hanson. The earliest published state- 
ment found to this effect is the following^^ written March 16, 1764, 
signed " A Member of the Society of Arts." 

" This plant was first taken notice of in North America, and seems to be a 
native of Virginia, where it grows, without cultivation, to a great height, on 
moorish, swampy grounds. 

13 Museum Rusticum et Commerciale, 2 : 61. 1764. 



VWE'i AM) I'.oU l : ACRU ri/l TKAI. lllSIOin' OI" I'lMo'l IU 



5 



" Some years aKo the seeds of this phmt were carried from Virginia, hy one 
Mr. Timothy Hanson, {o North Carolina, where it is now cidtivated hy tin- 
inhahitants; and from this circumstance it received the nanu- it now hears." 

In the same volume, i)agc is a letter written t(j the editor, A])ril 
4, 1764, bv a man sij^iiini;" himself "A h^riend to the Public," correct- 
ing the statcmenl made in the above letter: 

" I must, however. l)eK leave to set your correspondent right in one particular. 

*' He says, that the timothy grass was hrought into North C'arolina hy Mr. 
Timothy Hanson, from Virginia; this seems to he a mistake, as 1 am informed 
by a friend of mine, who has been in the country, that Mr. Hanson hrought 
the seeds of this grass into Carolina from New York. 

" That it may he cultivated in Virginia I make no doubt, as from its great 
use it must certainly soon spread over almost the whole continent of America. 
I am informed by the same gentleman, that this grass is, to great advantage, 
cultivated in some parts of Pensilvania." 

Another English publication^* has this account : 

Rocque has also cultivated another artificial grass called timothy-grass. 
This was, in the beginning of the year 1763, brought over from Virginia by 
Mr. Wyche. 

" It was called timothy, because it was brought from New York to Carolina 
by one Timothy Hanson, but if they had a mind to perpetuate the memory of 
this person, they should surely rather have called it by his sirname than his 
christian." 

The first mention that has been found in an American publication 
connecting the name of Timothy Hanson with the plant is that of 
Deane^° in 1790, as follows: 

" Timothy-grass, a coarse grass, but very agreeable to all sorts of cattle. It 
grows best on low and moist lands. It is a native of America, though some 
say it is not peculiar to this country. 

" It obtained its name, by being carried from Virginia to North Carolina by 
one Mr. Timothy Hanson. It is a species of foxtail; and is represented by the 
Rev. Mr. Eliot to be the same as herdsgrass, which he says was first found at 
Piscataqua, by one Herd, who propagated it." 

In the second edition of Deane's work pitblished in 1797, the name 
is given as Timothy Hanso instead of Hanson^ — evidently an error in 
printing. 

A man signing himself R., writing to the American Farmer^^ from 
Felicity Farm, Maryland, March 18, 1820, says: 

" For the introduction of timothy grass into the state of Maryland, the farm- 
ers are indebted to Timothy Hanson, the father of Jonathan Hanson, who built 

1^ Annual Register for the Year 1765, vol. 8, section headed "Projects," p. 
143. London, 1766. 

1^ Deane, Samuel, The New England Farmer; or Georgical Dictionary, ist 
ed., p. 285. 1790. 

16 American Farmer, 2 : 38. 1821. 



6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



the first Grist Mills on Jones' Falls, now forming a part of the city of Balti- 
more. This gentleman resided in Baltimore about seventy years ago ; and was 
the first person to bring the grass into cultivation. I believe Mr. Hanson was 
a native of one of the New England states, but whether he discovered the value 
of this grass, growing in the neighborhood of his mill, or brought the seed 
with him, I can not say ; but he had certainly the honour of introducing it to 
the public, and when it first came into fashion, it was called ' Timothy Hanson's 
grass,' and sold in ' Baltimoretown ' by that name. I should like to know how 
far back it was called Herd's Grass, to the eastward of Maryland. What has 
become of the Hanson family? Timothy had several sons. Jonathan, was 
one of your flour inspectors about the year 1769 or 1770, and was as well 
known as old Mr. Moore, the father of one of your present inspectors. That 
celebrated farmer and statesman, Timothy Pickering, is perfectly correct in 
his conjecture about the origin of the name of Timothy Grass and there are 
many old Baltimorians, yet remaining, who will delight you with an account 
of the fine crops of Timothy cut and cured on the Meadow, which was attached 
to the old mill now in ruins. Charles Constable, lumber merchant, is now the 
oldest native of Baltimore. He can probably tell you all about the Hanson 
family." 

Except for the discordant statements of his reputed wanderings 
this account of Timothy Hanson is the only one with circumstantial 
details that has been found. 

In American genealogies two families by the name of Hanson are 
recorded; one from Kent Co., Maryland, having in it no one named 
Timothy, and one mentioned in Savage's Genealogical Dictionary of 
New England,^^ as follows : 

^'''Pickering, Timothy, writing to the American Farmer (i: 390) from Wen- 
ham, Mass., Feb. 11, 1820, says: 

" Mr. Southwick, the learned author of the Treatise on Agriculture, in Section 
XI, published in your paper No. 86, discoursing on grasses, mentions Timothy, 
and says that ' in Europe it is called Herd-grass, Cat's-tail, or Phleum pratense, 
its botanical name'; but as the plant is of Yankee origin, we have chosen to 
retain the Yankee denomination. Dr. Elliot of Conn, who in the last century 
wrote several essays on field-husbandry in his third essay, printed in 1751, says, 
* There are two sorts of grass, which are natives of the country, which I should 
recommend; these are Herd-grass (known in Pennsylvania by the name of 
Timothy grass;) the other is fowl meadow, sometimes called Duck-grass, and 
sometimes Swamp-wire-grass. It is said that Herd-grass was first found in 
a swamp in Piscataqua (Portsmouth, N. H.) by one Herd, who propagated the 
same.' It is a fact that it is now known among farmers, generally in Massa- 
chusetts, and I believe throughout New England, only by the name of Herd's 
grass. From New England I have supposed that the seed was carried to Penn- 
sylvania, and there, or in the three lower counties, now the state of Delaware, 
being cultivated by a person whose surname was Timothy, the grass received 
his name; and under that name, was sent from Philadelphia to England. In 
such English books on agriculture, as have fallen in my way, it is uniformly 
called Timothy, or cat's-tail." 

18 Savage's Genealogical Dictionary of New England, 2: 352. 



VWVM AM) IIOIM': ACUICIM/IIIRAL IllS'lOin' Ol" IIMO'I IIN 



7 



"Hanson. Thomas, Hover, i057,"* frt'cni. 5 June. pioh. d. \()()(), as liis 

will was pro. 27 June. !()<)(). His wid. was K. by tlu- hid. His ch. wtTc Tobias, 
Thomas, h. a. Isaac; 'J iniotliy ; and two ds.'' 

There is no further iiifornialioii ahoiit the Tiinollix Hanson spoken 
of in Savage's (ienealogical Dictionary, though other nienihers of the 
family are accounted for in that and other New England localities. 
It is of interest to note that this Timothy ! Ian son is from tlie same 
locality as Herd. 

Ouinf-'' mentions a grant of land near Salmon l\'dls (N. If.) made 
to Thomas Hanson in 165CS. There is sufficient corroborative evi- 
dence in his account to identify this Thomas Hanson with the one 
mentioned by Savage. According to Quint's statement, Thomas' son 
Timothy was not of age when his father's will was probated in 1666. 
Quint states that Thomas Hanson had a great-grandson named Tim- 
othy, and mentions an older brother of this Timothy who was born in 
1702. This Timothy (who, according to Quint also had a son 
Timothy) might easily have been the one mentioned above as living 
in Baltimore about 1750 and introducing to the public what was there 
called Timothy Hanson's Grass." On the other hand, if timothy was 
introduced into Maryland about 1720, the introduction might have 
been made by Timothy Hanson, son of the original Thomas Hanson 
mentioned by Savage. The 1720 date rests solely on the statement of 
Vasey published in 1884, unless Vasey had access to some account that 
has escaped our search. It should be remembered that timothy was 
well known according to Franklin in 1747. 

The American origin of timothy as a cultivated crop seems scarcely 
to be doubted. In England it was a common grass in the fields known 
under the names of cat's-tail grass and meadow cat's-tail grass, but 
it was never cultivated nor considered valuable. Following its utiliza- 
tion in this country, it attracted interest in England through the mis- 
taken idea that the grass so successful here was new there. Seed was 
sent to England prior to 1746 under the name St. Timothy grass. 
According to the statement quoted below, it was again imported from 
Virginia in 1763.-- 

" Rocque has also cultivated another artificial grass called timothy-grass. 
This was in the beginning of the year 1763, brought over from Virginia by 
Mr. Wyche." 

19 Probably the date of the arrival of Thomas Hanson in America. 

20 Quint, Alonzo H., Genealogical Items Relating to Dover, N. H., in The 
New England Historical and Genealogical Register (published quarterly by the 
N. E, Hist, and Genealog. Soc), Vol. VI, p. 329. 1852. 

21 Ellis, Wm., 1. c. , • 

22 Annual Register for the Year 1765, 1. c. 



S JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



A letter from Mr. Rocque-^ to Mr. Corbet dated December 7, 1763, 
confirms the first part of the above statement. He says : 

" As to Timothy-grass, it grows prodigiously quick. I have sowed it for the 
first time in September last." 

Mr. Peter Wyche was chairman of the Committee on Agriculture 
of the London Society for the Encouragement of Arts, Manufac- 
turers, and Commerce (now called Royal Society of Arts) about the 
year 1760. He died some time prior to November 15, 1763. There 
is no published evidence that he ever visited America. A search 
through the Memoirs of Agriculture by Dossie, the Museum Rusti- 
cum et Commerciale, and other publications connected with the So- 
ciety of Arts, made with the hope of finding the record of Mr. Wyche's 
importation of timothy, was unsuccessful. 

Stillingfleet^* in a note dated September 14, 1763, on the gathering 
of meadow cats-tail seed says seed was brought from New England. 

" This is what is called Timothy grass lately brought from New England, 
as I am assured by a skillful botanist who has raised it from the seed." 

After a few years trial by English farmers it failed to meet with 
favor, as is shown by quotations below : 

"Its reputation here was short-lived, and deservedly; for it has no one good 
property in which it is not excelled by the fox-tail grass ; and besides this it is 
harsh, and late in its appearance. It is proper only for moist lands ; in a 
dry soil it makes a pitiful appearance." — Thomas Martyn.^s 

" It is very productive but coarse and late, and has no excellence, that we are 
acquainted with which the Alopecurus pratensis does not possess in an equal 
degree." — Wm. Curtis. 26 

" As to the burnet, spurry and timothy grass, although their virtues have 
been highly celebrated by many authors, yet I believe they have never been 
found to answer in the cultivation in any degree equal to the sanguine com- 
mendations bestowed on them by these authors, or advocates." — John Banister, 
of Kent.27 

Although Sir John Sinclair,^^ and others later made trials of 
timothy, it does not seem to have found a place in English agriculture 
except as a grass to use in mixtures. 

In this country from the time Jared Eliot recommended the culture 
of "herd grass," and Benjamin Franklin called it ''mere timothy," 

23 Museum Rusticum et Commerciale, i : 306. 1763. 

24Coxe's edition of Stillingfleet's work. Observation on Grasses, p. 258. 181 1. 

25 Martyn, Thomas, Flora Rustica, vol. i. 1792. 

26 Curtis, Wm., British Grasses. 1798. 

27 Banister, John, A Synopsis of Husbandry. London, 1799. 

28 SinclaiV, Sir John, Code of Agriculture. 1818. 



riiM'.K AM) r.oiM ; .\( .Ricr i/ituai. iiimok-n oi' iiMMiin 



9 



tlie importance of liinotlix has increased until. v\v\] as carlx as \\\v lirst 
part of tlu' nineteenth centnry, il l)ecanie the most important ha>- 
crop in the I 'nited States. A few references indicating tliis are given 
below in chronolos^ical order: 

1775. " A larKc iK^rtioii of lAory farm in Now I'JiKlaiul consists of meadow and 
pasture land ; * * ♦ the common hcrhiagc * * * is a grass which has 
made much noise in England under the name of Timothy." — 
" American."-" 

1787. " They begin, however, to sow some quantity of herd's-grass seed, which 
they call Timothy." (He is speaking of a locality near Morristown, 
N. J.).— Cutler.--«'> 

1789. Queries and Answers on the present State of Agriculture in Delaware. 

Q. What plants are cultivated * * * for cattle? 
i\ ♦ * * More especially timothy and clover are cultivated for the 
use of cattle. — Tilton.^i 

1790. " More needs not to be said here of a grass the great value of which is 

so well known in New England." — Deane.^"*- 
1799. " The properties of Timothy need not be here mentioned, as the plant 
and its properties are very generally known in America." — Park- 
inson. 

1801. " Timothy grass is extensively cultivated in the middle and northern 
States of the American Union." — Strickland. 

1804. " Timothy grass * * * makes the best hay and the greatest quantity of 

any known at. present in this country." — Roberts.^'' 

1805. " Timothy * * * according to the accounts of travellers in America, it 

constitutes the principal support of cattle and other animals." — 
Dickson. 36 

1807. " Timothy grass, or phleum pratense, is more extensively cultivated than 
any other grass in the United States." — Mease.s^ 

1818. "A well known and important grass, not a native, but now completely 
naturalized in this country." — Barton. 

1824. " This grass is extensively cultivated." — Bigelow.^^ 

29 American Husbandry, by an American (native of Sweden), i : 57. Lon- 
don, 1775. 

3^ Cutler, M., in Life, Journals and Correspondence, i : 288. 1888. 
3^ Tilton, James, in American Museum, 5: 276. 1789. 

22 Deane, Samuel, The New England Farmer; or Georgical Dictionary, p. 
285. 1790. 

33 Parkinson, R., The Experienced Farmer, vol. 2, Supplement, p. 8. 1799. 

34 Strickland, Wm., Observations on the Agriculture of the United States, 
p. 63. London, 1801. 

35 Roberts, Job, The Pennsylvania Farmer, p. 49. 1804. 

36 Dickson, R. W., Practical Agriculture, 2 : 833. London, 1805. 

37 Mease, James, Geological account of the United States, p. 225. 1807. 

38 Barton, Wm. P. C, Compendium Florae Philadelphicae, i : 47. 1818. 

39 Bigelow, Jacob, Florula Bostoniensis, 2d edition, p. 28. 1824. 



lO JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



1827. " Till within a few years our farmers rarely sowed any grass seedsy 
but those of clover and herd's grass or timothy, as it is called in 
middle states. "^0 

1846. " We are inclined to place timothy first in the list of grasses." — Allen." 

It is an interesting fact that almost as far back as there are publica- 
tions relating to early American agriculture, timothy was used not 
only as a crop to sow alone, but in mixtures with other grasses and 
with red clover. 

George Washington gives directions for its use in a letter written 
from Philadelphia to his overseers, July 14, 1793:*^ 

" The lowest and wettest part thereof is to be sown with timothy seed alone. 
All the other parts of it are to be sown with timothy and clover seeds mixed. 
* * * Where clover and timothy seeds are mixed and sown together, allow five 
pints of the first and three of the latter to the acre; and where timothy alone 
is sown, allow four quarts to the acre." 

There are also numerous other instances of its use in this way» 
Among them, the earliest are quoted : 

" Herds-grass, as good and profitable as any. Grows well on any soil except 
sandy and gravelly, when mixed with clover, as that decreases, this increases,, 
so that the crop of grass will hold out for several years — cut it just before it 
goes out of blossom, or a little sooner." — John Dabney.^^ 

" It is not uncommon in the ordinary husbandry, to sow lots of ground with 
clover and timothy seeds mixed." — J. B. Bordley.** 

" It is a common practice in Connecticut, to sow timothy and clover mixed."' 
— Job Roberts.^^ 

" Having sown the usual quantities of clover and herds-grass, I gave the 
whole a small dressing of yard manure."^^ 

The common practice of sowing clover and Herd's-grass in the spring, 
immediately after the sowing of the grain, is superior to that recommended by 
some European writers, of sowing them in the autumn after the grain crop 
is harvested. Clover and grass sown in the autumn, are in this climate, ex- 
tremely apt to be ' winter killed.' * * 

One other point regarding the grass, namely, its nativity in America, 
is a question partly historical and partly botanical. 

^'^Massachusetts Agricultural Repository and Journal, 10: 13. 1827. 

41 Allen, R. L., A Brief Compend of American Agriculture, p. 85. 1846. 

*2 Published in The Farmers Cabinet, vol. 7, no. 7, Feb., 1843. 

43 Dabney, John, An Address to Farmers, p. 54. Salem, 1796. 

44 Bordley, J. B., Essays and Notes on Husbandry and Rural Affairs, 2d ed.^ 
p. 12. Philadelphia, 1801. 

45 Roberts, Job, The Pennsylvania Farmer, p. 149. Philadelphia, 1804. 

46 Memoirs, Agricultural Society of Massachusetts, 4: 165. 1816.. 

47 Massachusetts Agricultural Repository and Journal, 5 : 353. 1819. 



riPKR AND iu)K'i': ACRK ri/rru.\i. iiisiom oi" 'i imoi iiy 



Many of tlio early af^ricullural writers believed il to be native of 
America and this idea was held by so lii.^li an anthority as Dr. Vascy."'* 
He sa} s : 

"It is iindoiilitfdlN iiuli.mMious in tlic nioiiiitain rcj^ions of New I^iigland, 
New York and the Kocky Alountaiiis." 

From a historical stan(li)()int it may snffice to point out that none of 
the early botanical explorers, with the exception of Cutler, mentions 
timothy, althoui;h it was in cultivation before the time of Kalm. 
Amono- these explorers are Cornuti, whose work on Canadian plants 
was published in 1635; Peter Kalm, who visited America in 1748 and 
1749 and traveled throughout the Eastern States and northward into 
Canada ; Clayton, wdio collected plants in Virginia, descriptions of 
which are published in Flora Virginica by J. Frederick Gronovius, 
1743; Bartram, v\^ho traveled from Pennsylvania to Canada prior to 
1751 ; Walter, who published his Flora Caroliniana in 1788; and 
Michaux, who collected throughout the Eastern States and Canada 
and published his ''Flora Boreali-Americana " in 1803. 

From the purely botanical standpoint the evidence that timothy is 
not native in North America would require an extended treatise, going 
into details of the different sorts of evidence by which such a con- 
clusion is reached. It suffices to point out that every recent botanical 
writer in dealing with the subject has considered without question 
timothy to be an introduction from the Old World. So far as New 
England alone is concerned, and this region is of particular interest 
because timothy was probably first cultivated there, the testimony of 
Prof. M. L. Fernald of Harvard University, the highest authority on 
the New England flora, should have greatest weight. Prof. Fernald 
writes as follows : 

" Gray Herbarium, Harvard University, 

Cambridge, Massachusetts, U. S. A. 

Prof. C. V. Piper, 

Bureau of Plant Industry, 
Washington, D. C. 

Dear Prof. Piper: 

I have just returned to Cambridge and find your letter in regard to Phleum 
pratense. I have never seen the slightest sign that P. pratense is native in 
New England or Eastern Canada. I have scoured the most primitive areas 
for years and have never come across the grass but once away from settle- 
ments. That was when a single specimen was found at a camp-site on Mt. 
Katahdin. 



Vasey, George, U. S. Dept. Agr., Misc. Report No. 32, p. 63. 1884. 



12 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



P. alpimim is the most abundant grass on some of the alpine tablelands of 
Eastern Quebec and is found less abundantly on the mountains of northern 
New England. The Herbarium gives no evidence that P. pratense is indige- 
nous with us. 

Sincerely yours, 

(Signed) M. L. Fernald." 

The grass is mentioned either as herd's grass or timothy in all of 
the works cited below. In most cases the reference is such as to imply 
that the crop is well known. In those publications marked with an 
asterisk the grass is said to be native to America. 



Year. Publication. 

1747-59.* Essays on New England Husbandry, by 
Jared Eliot (1760). 

1764. Memoirs of a Huguenot Family — Compiled 
from original autobiography of Rev. 
James Fontaine, etc., by Ann Maury, p. 
443. 1853. (A letter in this publication 
dated Jan. 2, 1764, acknowledges the re- 
ceipt of timothy-grass from Virginia.) 

1775. American Husbandry. By an American (na- 
tive of Sweden), i: 57. London. 

1787. Life, Journals and Correspondence of M. 

Cutler, I : 288. 

1788. Columbian Magazine, 5 : 503. 

1789. American Museum, 5 : 276. 

1789. Farmers Magazine, i : 257. 

1790. * New England Farmer; or Georgical Dic- 

tionary, by Samuel Deane (a second edi- 
tion in 1797). 

1792. Mr. Imlay, of New Jersey, in American Mu- 

seum, 12 : 265. 

1793. * The Practical Farmer, by John Spurrier, of 

Delaware (original American edition pub- 
lished at VVilmington). 

1796. An Address to Farmers, by John Dabney. 

Salem. 

1797. Agricultural Enquiries on Plaister of Paris, 

by Richard Peters. Philadelphia. 

1797. Tours into Kentucky and the Northwest 
Country. Three Journals by the Rev. 
James Smith of Powhatan Co., Va. 1783, 
1795, and 1797. (Published in Ohio 
Archaeological and Historical Society 
Quarterly, vol. 16 (1907), p. 390.) 

1799. The Experienced Farmer, by R. Parkinson. 
Philadelphia. 

1799. Monthly Magazine and American Review, 
i: 123. 

1801. Essays and Notes on Husbandry and Rural 
Affairs, by J. B. Bordley, 2d ed. Phila- 
delphia. 

1801. Turnip & Peafallows, with a design of Ro- 
tation of Crops, Recommended to the 
Farmers and Planters of the United 



What Called. 

Herds grass. 
Timothy. 
Timothy grass. 



Timothy grass. 

Herd's-grass. 

Timothy. 

Timothy grass. 

Timothy. 

Timothy grass. 

Timothy. 

Timothy grass. 

Timothy, Herd's-grass 

or Fox tail. 
Bulbous cat's tail. 
Timothy grass. 

Timothy grass. 



Herds-Grass. 

Timothy-grass. 

Timothy. 



Timothy. 
Timothy. 
Timothy. 

Timothy. 



i'iri:K AM) I'.oK'i': acuk ri. rrK.\i. iiisioky oi- timo'i iiv 



States of America. 15y Ki^•lKl^(l Parkin- 
son, p. 8, Washington C ity. 

1803. A Treatise on Practical I'^arniinn. I>y John 

A. Binns, of l>t)U(lon Co., Virginia. 

1804. * W'illricli, Domestic iMicyckjpaedia, 3: 195. 

First American edition edited by James 
Mease. 

1804.* The Pennsvlvauia I'\iniier, by lob Ivoberts. 
Philadelphia. 

1806. Memoirs Agricultural Society of Massachu- 

setts, vol. 4, 1816. (Letter from a man 
from Brookfield, Oct. 15, 1806.) 

1807. Geological Account. of the United .States, by 

James Mease. 

1814. Philadelphia Society for the Promotion of 
Agriculture. Memoirs, 3 : 330. 

1818. Philadelphia Society for the Promotion of 
Agriculture. Memoirs, 4: 156. 

1818. Compendium Florae Philadelphicae : Con- 

taining a Description of the Indigenous 
and Naturalized Plants found within a 
circuit of ten miles around Philadelphia. 
By William P. C. Barton. Vol. I. Phila- 
delphia. 

1819. Massachusetts Agricultural Repository and 

Journal, 5 : 353. 

1820. * The Farmer's Assistant, by J. Nicholson. 

Philadelphia. 



1820. The American Farmer, i : 390. Timothy 
Pickering, vv^riting from Wenham, Mass., 
Feb., 1820. 

1826. The Farmer's Library, by L. Lathrop, of 
Vermont. (Windsor.) 



1841. Farmer's Cabinet, 5 : 179. 

1846. Allen's American Agriculture, p. 85. 



'J'imothy. 
Timothy. 

Timothy. 
Herds-grass. 

Timothy grass ; 
Cat's tail grass, of Eng- 
land. 
Timothy. 

Timothy. 

Timothy-grass. 



Herd's-grass. 

Meadow-Cats-tail ; 
Timothy grass; 
Herds-grass ; 
(It is erroneously called 

Foxtail.) 
Timothy ; 
Herd-grass ; 
Herd's-grass ; 
Cats-tail. 

Meadow Cats Tail; 
Timothy grass; 
Herds Grass. 
(Erroneously called fox 

tail.) 
Timothy. 
Timothy ; 
Cat's tail; 
Herd's grass. 



Summary. 

From the data above quoted the important historical statements may 
be summarized as follows : 

1. According to the statements of Jared Eliot, first published in 
1747, timothy was first " found in a swamp in Piscataqua by one Herd, 
who propagated the same." 

2. Benjamin Franklin in 1747 refers to the grass in Pennsylvania 
as " mere timothy." 

3. Timothy seed was taken to England from America as early as 
1746. The later importation of seed into England by Mr. Peter 



14 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



W}xhe, often referred to by writers, was according to contemporary 
evidence in 1763. 

4. The name timothy is said by various EngHsh writers in 1764 and 
shortly thereafter, to be derived from one Timothy Hanson. Re- 
garding the identity of this man and his relation to the dissemination 
of the grass, the evidence is very conflicting. The most circumstan- 
tial account makes him a resident of Baltimore, though the same 
writer expresses the belief that Mr. Hanson was a native of one of 
the New England States. 



LNNDl'. AND la'TKi:: OSMOSIS IN SOILS. 



ON OSMOSIS IN SOILS.' 

C. J. LViNIMC AND J. V. DUI'KK, 

Macdonald CoLLiXiK, P. Q., Canada. 

For the sake of clearness we have divided this paper into three 
parts, as follows : 

I. A historical statement of our previous work on the osmosis of 
soils. 

II. Experiments in which we measured the osmotic pressures which 
were obtained when a column of very fine soil was used as a semi- 
permeable membrane and a concentrated soil solution as the active 
solution. 

III. An experiment to determine whether or not the pressures ob- 
served were due simply to the swelling of the soil column. 

I. Historical. 

It is usually stated that soil water is subject to three types of move- 
ment, namely, gravitational, capillary and thermal. In studying the 
movement of soil moisture the senior author was gradually led to the 
conclusion that in producing this movement there is some agency at 
work, other than those just stated. In considering what this agency 
might be he was led to the following theory. 

Theory that Soils Act as Semi-Permeable Membranes. 

It is possible (i) that sails act as semi-permeable membranes; (2) 
that the greater the depth of the soil the greater is its efficiency as a 
semi-permeable membrane; (3) that a soil solution moves through the 
soil by osmotic pressure from points where the solution is less con- 
centrated to points where it is more concentrated. 

In 1912 the senior author read two papers^ before the American 
Society of Agronomy at their meeting at Lansing, Mich. The results 
presented indicated that the above theory is true for a heavy clay 

^ Read before the Royal Society of Canada, May 27, 1914. 

2 Lynde, C. J., Osmosis in Soils : Soils Act as Semi-Permeable Membranes, 
Proc. Amer. Soc. Agron., 4 : 102-108. 1912. Also in Journal of Physical Chem- 
istry, 16 : 759. December, 1912. 

Lynde, C. J., and Bates, F. W., Further Studies in the Osmosis of Soils, Proc. 
Amer. Soc. Agron., 4: 108-121. 



1 6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



subsoil. It acts as a semi-permeable membrane, its efficiency as a 
semi-permeable membrane increases with its depth, and the soil mois- 
ture moves through the soil membrane from points of less concentra- 
tion to points of greater concentration. 

Last year he had the, honor of reading a paper^ before this society 
in which he gave some results obtained by using the soil constituents 
as semi-permeable membranes. In the mechanical analysis of soils, 
the soils are divided into grades according to the size of soil particles. 
The grades are known as sands, silt and clay. These are the soil con- 
stituents. We found that the smaller the soil particles in a soil con- 
stituent the greater is the efficiency of the constituent as a semi-per- 
meable membrane. 

In the papers read in 1912 the greatest osmotic pre ure recorded 
was 5.6 grams per square centimeter. This corresponds to a water 
column about 2 inches high. In the paper read before this society 
last year the greatest osmotic pressure recorded was 42.5 grams per 
square centimeter, corresponding to a water column about 16 inches 
high. This year we have carried this further and we have obtained, 
as is shown below, an osmotic pressure of 352 grams per square 
centimeter, corresponding to a water column of over 11.5 feet. 

II. On the Osmotic Pressure Obtained by Using a Column 
OF Very Fine Soil as a Semi-Permeable Membrane, 
and a Concentrated Soil Solution as the 
Active Solution. 

A loam soil which was known to contain a considerable amount of 
very fine soil was used. The loam was soaked in bulk over night in 
a pan of distilled water. From this mud eight shaker bottles were 
loaded each with approximately 5 g. of soil, 150 c.c. distilled water and 
5 drops of ammonia. 

After one hour in the shaker the bottles were allowed to stand for 
15 minutes and the liquid was decanted into an enameled pan which 
was then placed in an oven at 110° C. A further 150 c.c. of distilled 
water was then added to each bottle and the bottles were again 
shaken for one hour. After standing for 15 minutes the liquid was 
again decanted and added to the liquid obtained from the first shaking. 
To sterilize the liquid and free it from ammonia it was brought to 
about 100° C. in the oven and then placed over a burner until decided 

3 Lynde, C. ]., and Dupre, H. A., Osmosis in Soils: The efficiency of the Soil 
Constituents as Semi-Permeable Membranes, Journal Amer. Soc. Agron., 5 : 
102-106. 1913. Also in Transactions of the Royal Society of Canada, Third 
Series, Vol. VII, 1913. 



^^•Nl)l••. AND la'i'Ki:: osmosis in soils. 



'7 



cbiillili* III took plart'. TIh- li(|iii(l was allowed lo cool over ni^lit and 
was llicn (Iccanlcd into a J.ooo c.c. cxlindcr. It was allowed to settle 
in the cylinder for seven days. 

A cxlinder was lillcd with li(|nid in a sinnlar manner each da}' for 
seven da\s. After seven days the li(|nid in the lirst cylinder was de- 
canted from the sediment and evaporated down in an enameled pan in 
an oven at 1 10° C. \ext da\ the li(|ui(l from the second cylinder was 
added to this pan. 'i^iis was conlinned each day for seven days. The 
liquid was tinall\' evai)orate(l down until it was a rather thick s\rup. 



The apparatus used is shown in figure i. Two glass tubes approxi- 
mately 15 cm. long and i cm. in diameter were closed at one end with 
one layer of cotton cloth. They were then filled with the thick hot 
liquid and placed in cups of the centrifuge. The cups were filled with 
hot distilled water to the level of the liquid in the tubes. The cen- 
trifuge w^as run at top speed for 15 to 30 minutes; the liquid was then 
decanted from the sediment and replaced by fresh thick liquid. This 
was continued until the sediment reached the desired thickness or until 
the thick liquid was exhausted. The centrifuge made 1,300 r.p.m. 
and the center of the column of sediment in each tube was 25 centi- 
meters from the center of the axes of the centrifuge. The liquid 
remaining in the tubes after the last settling w^as used as the soil 
solution. 



Ho'K' the Apparatus Was Set Up. 



MA/VJOMETER— 



MERCURY- 





SOIL SOLUTION 



COTTON CLOTH 



OfSTULED WATER 



Fig. I. — Apparatus used in measuring osmosis in soils. 



1 8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



An open arm mercury manometer was then attached to each tube 
and the tubes were placed in distilled water. After the observations 
on the pressure had been completed, the electrical resistance of the 
soil solutions was compared to that of a .02N KCl solution. 

We made two separate experiments and repeated the second experi- 
ment twice, using the same soil and solution as in the second experi- 
ment. The results obtained are shown in Table i. 



Table i. — The Osmotic Pressure Observed in the Various Experiments. 







Osmotic Pressure. 


No. of Experiment. 


No. of Tube. 












Hg. 


H,0. 


H2O. 






cm. 


cm. 


feet 


Firsti 


I 


15-5 


210.8 


6.9 


Do 


2 


23.8 


323.7 


10.6 




I 


259 


352.2 




Do 


2 


lost 






Second repeated, 3 first trial 




17.0 


231.2 


7.6 


Second repeated, second trial 




20.3 


276.1 


9.0 



1 Duration of experiment, 14 days. Depth of soil column, i, 7 cm. ; 2, 4 cm. 
Resistance of soil solutions compared to .02N KCl solution, soil solution 70 
ohms, .02N KCl solution 270 ohms, at 18° C. 

2 Duration of experiment, 6 days. Depth of soil column, approximately 6 
cm. Electrical resistance of soil solution, 60 ohms; of 02N KCl solution 270 
ohms, at 18° C. 

3 Duration of first trial three days, at the end of which time the manometer 
was accidentally broken. It was replaced and the experiment started again. 
Duration of second trial ten days. 

III. An Experiment to Determine Whether or Not the 

Pressure Observed is Due to Swelling of the Soil Column. 

It occurred to us that the pressures we observed might be due to 
the swelling of the soil column. To settle this point we prepared 
soil as above, allowing it to settle in water for 4 days. We then set 
up two tubes as usual and measured the pressure developed. We 
also set up a third tube in the same way except that we inserted a solid 
rubber stopper instead of the layer of cotton cloth. Thus no move- 
ment of moisture due to osmotic pressure could occur. If then we 
observed a pressure it could not be due to osmotic pressure but must 
be due to some other cause such as the swelling of the soil column. 

The two tubes set up in the ordinary way developed osmotic pres- 
sures, but less than those given above. 

The third tube with the solid rubber stopper not only did not 
develop any pressure but gave a negative pressure. This indicates 
that the soil solution is absorbed and that the total volume of soil plus 
solution decreases. 



I.N NDI". AM) Dri'Ki;: (iSMOSIS I i\ .SOILS. 



19 



W'c lluMi poured llic soil solution out of llu- tiiht- with tlic rnhhcr 
sloi)i)cr and added distilled water. .Xi^ain a nej.;ative reading was 
obtained and nineli j^reater than with the soil solution. This indicates 
that the soil column absorbs water more readils than it absorbs soil 
solution and that there is a s^reater decrease in total volume. The 
results of this experiment are shown in Table 2. 



Tahle 2.— fill' Osmotic rrcssiin's Observed in 'I'lihi's 1 and 2 and ihc Negative 
I'ressures Obsenrd in Tube 



Tube. 


Pressure, Hg. 


Time. 




cm 

8 

9.1 

— 3-7 
—10.3 


days 
15 

b 
15 









1 Depth of soil columns: i, 7.5 cm.; 2, 8.5 cm.; 3, 5.5 cm. Electrical resist- 
ance of soil solution: i, 70 ohms; 2, 85 ohms; 3, 80 ohms; of .02N KCl solu- 
tion, 270 ohms at 18° C. 



Conclusions. 

I. -Using a concentrated soil solution as solution and a column of 
soil approximately 2.5 inches deep as semi-permeable membrane we 
have observed an osmotic pressure ecjual to the pressure exerted by a 
column of water 11.5 feet high. 

II. The results indicate that the pressures observed are not due to 
the swelling of the soil column. 

They indicate also that the pressures observed are due to osmosis^ 
as follows: (a) the semi-permeable membranes used in investigations- 
on osmotic pressure are colloids; (b) there is strong evidence that the 
action of semi-permeable membranes is one of unequal absorption. 
One liquid is absorbed more readily than the other and the movement 
is toward the liquid least absorbed. The soil we have been using as 
a semi-permeable membrane resembles the ordinary semi-permeable 
membranes in both ways : (a) it is quite probable that it is in a col- 
loidal state; (b) it absorbs water more readily than it does a soil solu- 
tion and the movement is toward the licpid least absorbed, namely, 
toward the soil solution. 



20 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



GRAIN CROP MIXTURES.! 

C. W. Warburton, 
Office of Cereal Investigations, U. S. Department of Agriculture, 

In nature, plant associations are the usual thing, plant segregations 
the exceptional, though there are of course areas which are covered 
with a single species of plant to the virtual exclusion of all others. 
In agriculture, except in the production of forage, partial or complete 
segregation rather than crop association is the rule or at least the 
intention, for the plants which appear in association with our corn or 
wheat or cotton quite commonly are there contrary to the desire rather 
than at the volition of the grower. We call them weeds. Crop asso- 
ciations, however, are much more common than appears at first glance. 
In addition to the numerous crop mixtures of grasses and legumes, 
one might mention such common associations as corn and cowpeas, 
the small grains with the grasses and clovers, and mixtures of the 
various cereals. These crop associations, it seems to me, fall naturally 
into three classes. 

The Three Classes of Crop Associations. 

1. Mixed Crops or Crop Mixtures. — In actual crop mixtures, the 
components are grown together during all or practically all the life of 
the crops and are harvested together. They may or may not be sown 
together. To this class belong most of the forage mixtures, such as 
timothy and clover, corn and cowpeas or sorghum and cowpeas for 
hay or silage, oats and peas, rye and vetch, and the like. Here also 
belong the cereal crop mixtures, such as oats and barley, oats and 
wheat, wheat and flax, and winter oats and rye. The cereals and field 
peas are also grown together for the production of gi*ain. Obviously, 
mixed crops may be made up of two, three or more components. 

2. Companion Crops. — When two or more crops are grown together 
on the same field but are not sown or harvested together, though the 
life of the crops is practically the same, they may well be called com- 
panion crops. A good example of this class is the growing of cotton 

1 Read before the Washington (D. C.) Section of the American Society of 
Agronomy, Jan. 20, 1915. 



WAKI'.I K ION : (.KAI.N (KOl' MIXIIUIS. 



21 



ami C()\vi)cas in alternate rows, as is often practieecl in tlu' Sontli. 
SiniilarK , this class ol' associations inclndes the K''"^^ '"J^ (-'nvvpeas 
or soy beans with corn, whether in alternate rows or when the le^j^nmc 
is scnvn between the rows at the last cnh ivation, for the crops arc 
neither sown nor harvested toj^ether. The combination of corn and 
])unipkins so common throni^bout the Northern Slates and the 
/.ilian custom of j^rowini;- corn and rice toL^ether as described by 
Dorsctt- are other examples of companion crops. 

3. Tandem Crops? — In this class of association, the cro])s arc 
j^rown together only during a part of the life of one or both and they 
are not harvested together. The most familiar example, perha])s, of 
tandem crop association is the growing of a cereal wdth a biennial or 
perennial forage crop or crop combination, such as timothy and clover. 
Here, the two crops may be sown at the same or at dififerent times 
(an example of the latter is the sowing of clover seed in late winter 
or early spring on fields of fall-sown grain), but most of the growth 
of the second crop in the tandem is made after the first crop is 
harvested. Other examples of such combinations are afforded by the 
practice of sowing some winter annual, biennial or perennial in corn 
at the last cultivation, as crimson clover, wdnter wheat, or timothy and 
clover; the sowing of vetch, bur clover or crimson clover in cotton 
fields ; and rape with wheat, oats, or barley. An odd combination 
recently reported by an Austrian investigator* is that of wheat and 
carrots. Another is the Algerian one described by FairchikP of 
alfalfa in rows with wheat between the rows. 

A peculiar phase of tandem cropping which might perhaps be called 
relay cropping is found in the Southern States. Two examples of this 
phase are the combinations of Bermuda grass and bur clover and of 
oats and Johnson grass. Bermuda grass makes its growth only in 
w^arm weather, starting late in spring and being killed by the first frost 
of fall. Bur clover, on the other hand, is a winter annual, starting 
with the approach of cool weather in the fall, growing through the 
winter, producing seed and dying soon after Bermuda grass begins 
to grow in the spring. Thus in the South, particularly on certain 
soils, a pure Bermuda grass lawn or pasture in the summer may show 
an equally pure stand of bur clover in the winter. It is not an un- 

2 Dorsett, P. H., in an unpublished paper presented at the Washington (D, C.) 
Section of the American Society of Agronomy, Dec. 18, 1914. 

3- For the suggestion of this term the writer is indebted to Mr. C. R. Ball. 

^Grabner, E., Weiner Landw. Ztg., 64 (1914), No. 23, pp. 208-209. Noted 
in Exp. Sta. Record, 31 : 735. 

spairchild, D. G., Cultivation of Wheat in Permanent Alfalfa Fields, U. S. 
Dept. of Agr., Bur. Plant Indus. Bui. No. 72: 5-7. 1905. 



22 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



common practice in some parts of the South to sow oats on Johnson 
grass meadows which have been disked or shallow plowed, harvest a 
crop of oats and then get one or two crops of Johnson grass hay later 
m the season from the same field, perhaps repeating the same process 
the following year. The Johnson grass and bur clover relay is also 
practiced. 

Grain Crops Grov/n in Mixtures. 

The growing of crops in associations is an old custom, just how old 
I can not say. It seems to be followed pretty generally over the 
world, but perhaps reaches its highest development (if the making of 
queer mixtures may be so termed) in India. The growing of grain 
crops in mixtures is practiced to some extent in Europe, though the 
area devoted to mixed grains appears to be decreasing. In America, 
mixed grain crops are rather common in eastern Canada, particularly 
in Ontario, and much less common in our Northern States. 

The area devoted to mixed grains in 1914 in all Canada is estimated 
as about 475,000 acres, as compared with about 1,500,000 acres in 
barley for the same year. In Ontario alone, the area in mixed grains 
in 1914 is estimated at 344,000 acres, while the acreage in barley is 
estimated at 461,000 acres. The acreage in oats is of course very 
much larger. No figures are available on the acreage sown to mixed 
grains in the United States, but it is very small in comparison with 
that of any of our leading cereals when sown alone. Bailey® states 
that " Wheat and oats are frequently grown in mixtures through this 
section of the northwest (Minnesota), such mixtures being commonly 
known as * succotash.' " Evans^ has reported the sowing of flax with 
winter wheat, but this was on fields where the wheat had partially 
winter killed and the flax was sown in the spring to more fully occupy 
the land, so that the association was not a mixture in the sense in 
which the term is here used. Other mixtures which are grown in a 
limited way for the production of grain are those of barley and oats, 
spring wheat and flax, and winter oats and rye. 

The principal reason for growing grain crops in mixtures is for the 
increase in yield which may be produced. The growing of oats or 
barley with peas (for under certain conditions peas must be considered 
a grain crop) helps to keep the peas more erect and makes the crop 
easier to harvest. Just why a mixture of barley and oats, for instance, 
is quite likely to yield more pounds of grain to the acre than either 

6 Bailey, C. H., The Composition and Quality of Wheat Grown in Mixtures 
with Oats, Jour. Am. Soc. Agron., 6: 215. 1914. 

Evans, M. W., Sowing Flax in Winterkilled Wheat Fields, U. S. Dept. Agr., 
Bur. Plant Indus. Circ. No. 114: 3-7- IPU- 



WAKHriMOX : (.UAIX (KOI* M I x'inuics. 



23 



crop wluMi sown aloiK' is Ii.ird lo sa\ . With associations of a Icj^unic 
and non-lc.!;nnic. llic additional j^rowdi may l)c dnc wholly or in part 
to the snpply of nitroi^i-n plac'cd at the disposal of the non-lc^(iimc by • 
the legume. Lyon and Ili/./cir have shown that under certain condi- 
tions there appears to he a nuitual stinudation and added growth of 
])lants in mixtures, whether or not one is a legume. Kaserer," an 
Austrian, states that the develo])ment of the roots of plants in mix- 
tures is (|uite (litTerent from that t)f the roots of the same ])lants in 
l)ure cultures, the surface soil being much more completely filled with 
roots in the mixtures. 

KXPKRIMKNTS IN THE UnITKI) StATKS. 

The ex])eriments with mixtures of grain crops within the limits of 
the Ignited States are remarkably few in number. Those which have 
been made were not continued long enough or were not made with the 
right mixtures to obtain the best results, but a review of them should 
be of interest. 

Morrow and Hunt^*^ tested various mixtures of oats and spring 
wheat at the Illinois station in 1889 and 1890, in comparison with 
2^/ bushels of oats sown alone and with 2 bushels of wheat alone. 
To quote from their statement : 

" It is the practice of some farmers in a limited way to sow oats and spring 
wheat together. * * * It has been claimed that spring wheat of good quality 
has been raised in this way, while when sown alone it was more or less a 
failure. The total yield of grain is said to be greater." 

In 1889, the wheat crop was almost a failure, but weather condi- 
tions w^ere more favorable for wheat in 1890 and a better yield was 
produced. In 1889, only one of the mixtures exceeded in yield the 
average of two plats sown to oats alone, while the average yield of the 
six mixtures was at the rate of 1,140 pounds of grain as compared 
with 1,300 pounds to the acre of oats alone. In 1890, three of the six 
mixtures yielded more and three yielded less than the oats sow^n 
separately ; the average of all the mixtures was 840 pounds and of the 
oats alone 820 pounds. For the two years, the mixtures in which ^ 
bushel of wheat was sow^n with 2 bushels and with 25^ bushels of oats 
yielded practically the same as 2>^ bushels of oats alone; all the other 

s Lyon, T. Lyttleton, and Bizzell, J. A., Is there a Mutual Stimulation of 
Plants Through Root Influence?, Jour. Am. Soc. Agron., 5: 38-44 1913. 

9 Kaserer, H., Ztschr. Landw. Versuchsw. Osterr., 14 (1911), No. 8. Noted 
in Exp. Sta. Record, 26 : 129. 

10 Morrow, George E., and Hunt, Thomas F., Field Experiments with Oats, 
1890, Univ. of 111. Agr. Exp. Sta. Bui. No. 12 : 358-360. 1890. 



24 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



mixtures fell considerably below the oats in yield. Morrow and Hunt 
concluded that there was no advantage in sowing spring wheat with 
• oats. It may be noted, however, that spring wheat is not well adapted 
to central Illinois. 

Hays^^ conducted an experiment with oats and wheat mixtures at 
the Minnesota station in 1891, comparing 4 mixtures of varying pro- 
portions with two rates of seeding for oats and two for wheat. The 
average yield from the oats alone was 2,914 pounds to the acre ; from 
the mixtures, 2,902 pounds ; and from the wheat, 2,331 pounds. The 
highest yield, however, was from a mixture sown at the rate of 2^ 
bushels of oats and J/2 bushel of wheat to the acre. This plat yielded 
at the rate of 3,196 pounds of grain to the acre, while the highest 
yield of oats alone was 3,109 pounds and of wheat alone, 2,463 pounds. 
The third highest yield, 3,060 pounds, was from a mixture sown at the 
rate of 2^ bushels of oats and ^ bushel of wheat. 

Atkinson, at the Iowa station, grew mixtures of White Russian 
oats and Bluestem wheat for two years (1899, 1900), in comparison 
with each variety sown separately. In every case, his rate of seeding 
was 8 pecks to the acre, thus combining 4, 5, 6 and 7 pecks of oat.s 
with 4, 3, 2 and i pecks of wheat respectively. For the two years, 
the highest average production was 1,860 pounds, this being from a 
mixture of 4 pecks of oats and 4 pecks of wheat. All the mixtures 
yielded better than either grain sown separately, the average yield of 
wheat alone being 1,420 pounds and of oats alone, 1,205 pounds. Of 
this experiment Atkinson^- says : 

" So large an increase as the above could not always be expected by mixing 
grain, but the fact is established that larger returns may be obtained from a 
mixed crop than when each grain is seeded separately. In this case the in- 
crease can be accounted for by the crop standing better and rusting less when 
the oats and wheat were mixed." 

Balentine^^ of the Maine station reports the results of a single 
year's test conducted in duplicate on plats of about ^ acre each, in 
which a mixture of equal parts by weight of wheat and oats sown at 
the rate of 64 pounds to the acre was compared with 48 pounds of 
oats sown alone and with 96 pounds of wheat alone. The two plats 
of oats produced at the rate of 1,946 pounds of grain to the acre, 
those sown to the mixture 1,814 pounds and those to wheat 1,410 
pounds. The yield of straw from the mixture was slightly more 
than from either crop alone. Balentine says : 

11 Hays, W. M., Grain and Forage Crops, Minn. Exp. Sta. Bui. 40 : 276, 277. 
Dec., 1894. 

12 Atkinson, James, Field Crop Experiments, Iowa Sta. Bui. 45 : 220. 1900, 

13 Balentine, W., Maine State Coll. Exp. Sta. Ann. Report for 1891, p. 144-5- 



WAUIU R ION 



(.l< \ l \ ( Uol" M I X'l TRI-.S. 



25 



" Tlu" trial is dcciilcdly in t"a\<>i of oats soparalcly as cotiiparrd with oals 
and wlu-at mixed, and oats and wluat iiiixi'd, as coinpari-d with wlu'at alone. 

"These results are in oi)position to the teaehinKS of many of our host 
farmers. 

" Tlie conelnsion of the writer is that the crop that yields the larger nnndxT 
of pounds per acre vvlien grown alone will not he henef'ited hy mixing with a 
crop that produces a less nuniher of pounds to the acre." 

This conoliisioii seems lo be well founded when there is a wide dis- 
])arity in the \ ields of the two crops when sown sei)arately, as was true 
in this instance. 

Canadi.\n Expi:ri mknts. 

The great mass of American data on grain crop mixtures is to be 
gleaned from the reports of the experimental farms maintained by the 
Dominion of Canada and from the reports of the Ontario Agricul- 
tural College Experiment Farm, particularly the latter. A few ex- 
periments with mixed grains have been conducted on the Central Ex- 
perimental Farm at Ottawa, Ontario, but the tests made by Professor 
Zavitz at Guelph have been most complete and convincing. Tests 
have also been made at some of the branch experiment farms, as at 
Nappan, N. S., Brandon, Man., and Agazziz, B. C, but most of these 
have been for one year only, so that they will not be discussed here. 

At Ottawa, Grisdale^"^ conducted tests of several grain mixtures on 
field plats of one to two acres each for five years, 1 900-1 904. This 
test included peas alone, barley alone, and oats alone, in comparison 
with mixtures of peas and oats ; oats and barley ; barley, oats and peas ; 
and wheat, barley, oats and peas. By far the largest yield, 3,751 
pounds to the acre, was obtained from oats alone; the mixture of oats 
and barley ranked second, and barley alone, third. 

In a later test for three years (1904-1906), Saunders^-^ compared 
mixtures of wheat and oats, wheat and barley, oats and emmer, and 
oats and barley. He did not, however, report the yields of the various 
crops when grown separately. For the three years, the highest yields 
were produced by two mixtures of oats and barley, 2,360 and 2,347 
pounds to the acre. 

The first experiment with grain crop mixtures reported by Zavitz 
was begun in 1893 and continued for six years. In this experiment, 
all the possible combinations of oats, barley, wheat and peas were 
compared, as follows : Oats and barley ; oats and wheat ; oats and peas ; 

^* Grisdale, J. FI., Canadian Exp. Farms Reports, 1900, p. 84; 1901, p. 301; 
1902, p. 84 ; 1903, p. 82 ; 1904, p. 98. 

1^ Saunders, C. E., Canadian Exp. Farms Reports, 1904, p. 275; 1905, p. 225; 
and 1906, p. 251. 



26 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

barley and wheat ; wheat and peas ; barley and peas ; oats, barley and 
wdieat : oats, barley and peas ; oats, wheat and peas ; barley, wheat and 
peas ; and oats, barley, wheat and peas. For the six years, the aver- 
age yield from a mixture of oats and barley was 2,261 pounds of 

MIXJUBB AVERAGE. YIELD OP GRAIH. POOHDS PES ACRB» 

Barley and IHH^HHIIii^HHHHHBIHHIHHH^HiHHH 2,&61 ll>s> 



Barlsy, peae and oats ■■■■■■■■■■■■■■■■■^^■■HHi 

Barley, wh«at and oate ^^^^■■■^^■■■^■^■■■■i^M 2,067 



Peae and ^HHBl^^H^^HI^^HHHHBBHiH^BHM 1,986 

Sarley, peas, wheat and oats ■■■■■■■■^■^■■■■■■■■■■l 1,955 



Wheat and oats wmm^^^^mmam^m^^^Km^^^^m 1,921 

vh^^at and oats IH^H^^H^HHHHi^HHMlMHH 1.860 



Berley and peee ■■^^■^^■^^■^■^■■■^^^H 1,760 

Barley, peas wheat ■■■■■■■■■■■■■■■■■■I 1.665 



Wheat and barley ^^^^^^^^^^^^^^^^HIMM^B 1,558 

Peas and wheat ■■■■■■■■■^^■■■B 1,322 

Fig. 2. — Graph showing average yield in pounds per acre obtained in a six- 
year test of various mixtures of grain crops at the Ontario Experiment Farm, 
1893-1898. 

grain to the acre; of oats, barley and peas, 2,101 pounds; and of oats, 
barley and wheat, 2,067 pounds. The yields from the other combina- 
tions ranged from these figures down to 1,322 pounds to the acre from 
the mixture of peas and wheat, as shown in figure 2. The yields of 
the different grains grown separately is not stated, but on this point 
Professor Zavitz^*^ says : 

" When a comparison is made between the different grains grown separately 
and the same grains grown in mixtures, it is found, in about 90 percent of the 
experiments, that the mixtures produced a larger yield per acre than the same 
grains grown separately." 

Having determined that the largest yield was obtained from a mix- 
ture of barley and oats, Zavitz began experiments to show at what 
rates these grains should be sown. In the first of these tests, nine 
different rates of seeding were tried. One-half bushel of oats was 
sown in mixture with jX, i and i^ bushels of barley, i bushel of 
oats with I and i^ bushels of barley and i^ bushels of oats with 
^, I and 15^ bushels of barley. Zavitz^" summarizes the results as 
follows : 

" The experiment has been conducted for six years in succession. The aver- 
age results show that the greatest number of pounds of grain per acre was 

10 Zavitz, C. A., Ontario Agr. Coll. and Exp. Farm Ann. Rept.; 23 : 178. 1897. 
179. 

17 Zavitz, C. A., Ontario Agr. Coll. and Exp. Farm Ann. Rept., 31 : 178. 1905. 



VVAKIU K rox : (.kai .x ( koI' m I x'l i •uI':s. 



27 



])r(»(huH'(l from ii iiiixtni i' of 1 hiislu l of oats (M 1I)S. ) aiul 1 hiislu'l (;f harlcy 
(4S lbs.) per acre, or a tolal anioiint of S_> pounds of mixed seed per ;urc." 

Ill a later (est. rondiictcd for tlic live veai-s from KjO/ to i<;ii, in 
wliicli 4 and 3 pecks of oats were sown in each of the nine possible 
eoinhiiiations willi 3, 4 and 5 ])ceks of harlev (i. e., 3 w illi 4 and 5; 
4 with 3, 4 and 5 ; and 5 with 3, 4 and 5), similar results were ol.'taincd. 
The liiL^liest averai^c \iel(l, 2,(^^^) pounds to the acre, was produced 
from the mixture of 4 pecks of oats and 4 pecks of l)arley and the 
next hij^hest from the two mixtures that most nearly a])i)roximated 
that rate. 3 i)ecks of oats with 5 ])ecks of harle\' and 5 i)ecks of oats 
with 3 pecks of barley. Of these two tests, Zavitz sa\ s : 

" An exceedingly interesting feature of the two experiments in which nine 
different proportions of oats and barley were used in combination, is the fact 
that the same mixture that gave the highest results in the first test of six years 
also gave the highest results in the other experiment of five years, the mixture 
being four pecks of oats (34 lbs.) and four pecks of barley (48 lbs.) or a total 
of 82 pounds of the mixture to the acre."^^ 

Professor Zavitz was apparently not entirely satisfied that in oats 
and barley he had obtained the combination which produced the 
maximum yield of grain, for in 1902 he began a series of experiments 
in wdiich a mixture of i bushel of oats and bushels of barley were 
compared with the same mixture to wdiich ^ bushel of some other 
grain had been added. The other grains which were added to the 
mixture in this way were durum wheat, emmer, flax, and hull-less 
barley. The combination of oats and barley yielded more, in a five- 
year test, than any of the mixtures to which some other grain was 
added. 

Having determined the kinds of grain to grow in combination and 
the rate of seeding which gave the best results, he attacked the problem 
of determining the best varieties of each grain to use in the mixture. 
To quote Professor Zavitz again : 

" If barley and oats are grown together, it is, of course, important to secure 
those varieties that will mature about the same time. In order to do this, it is 
necessary to use a very early variety of oats with an ordinary ripening barley, 
or a very late variety of barley with an oat which matures at an average date. 
Of all the varieties which we have used in combination, we have found that 
the Early Daubeney oats and Mandscheuri barley make a very excellent com- 
bination. Another mixture which has given very good satisfaction is the 
Siberian or Banner oats and the Chevalier two-rowed barley.''^^ 

Still another elaborate experiment with grain mixtures was begun 
by Zavitz in 1907 and continued for five years. Previous tests had 

1^ Ontario Agr. Coll. and Exp. Farm Ann. Rept., 37: 188. 191 1 (1912), 
1^ Ontario Agr. Coll. and Exp. Farm Ann. Rept., 31: 179, 180. 1905. 



28 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

convinced him that the presence of barley in the mixture was essential 
if the largest yields were to be obtained, so every one of the nineteen 
mixtures included barley and in thirteen of them the Manchuria barley 
was used. One bushel of each crop was sown to the acre, the combi- 
nations all being of two kinds of grain only. The 13 mixtures with 
Manchuria barley included 5 varieties of oats, black hull-less and 
white hull-less barley, rye, emmer, durum wheat, flax and 2 varieties 
of field peas. The largest yield for the five years was produced from 
the mixture of Manchuria barley and Alaska oats, 2,436 pounds to 
the acre ; the second highest from Manchuria barley and Daubeney 
oats, and the third from Manchuria barley and flax. The lowest 
yield, 1,940 pounds to the acre, was from the mixture of Black Hull- 
less barley and common emmer. In every case, barley made up more 
than 50 per cent of the crop produced, the range being from 52.86 
per cent in the mixture of Himalaya (Guy Mayle) Hull-less barley 
and Siberian oats to 91.98 per cent in the mixture of Manchuria barley 
and flax. In the mixtures of oats and Manchuria barley, the per- 
centage of barley, which was slightly less than 60 in the original mix- 
ture, ranged from 67.78 to 74.87 in the resulting crop. 

Conclusions. 

From these numerous experiments, it seems that a few general 
principles may be deduced. These are : ( i ) Grain crop mixtures may 
be expected to yield more than the grains composing them, if there is 
only a slight difference in the yield of the components when grown 
separately, but if the components differ considerably in yield the prod- 
uct of the mixture is likely to be intermediate between them. (2) 
The rate of seeding for the mixture should not be materially, if any, 
greater than for the components when sown separately. (3) Obvi- 
ously, the highest-yielding varieties which will mature at the same 
time -should be chosen. 

Whether or not the farmer can afford to grow grain crop mixtures 
rather than some one or more of the grains separately will depend on 
how large an increase in yield may be expected from the mixture ; on 
whether the mixture can be used as satisfactorily or economically for 
feed as the components separately ; on the salability of the mixture as 
feed grain; and on the cost of separation, if separation is necessary. 
For instance, the growing of oats and wheat in mixture would be un- 
profitable if the increase in yield over the mean yield of the two crops 
was not large enough to more than pay the cost of separation. 
Further, it would be unwise to grow barley and oats together if the 



I'.KII.I'I.K AK'I I( l.i:S. 



29 



croj) could !U)t be fed or sold i)r()rilal)l\ as I'eed j^raiii. t<'i- ilic se]>ara- 
lion of oats and l)aiie\' is difriciill. There seem In l)e cnoii^^h ad- 
vantages to the practire of i^rowin;^- .strains in mixture, however, to 
make it desirable for >ome of our northern stations to undertake some 
experiments with grain mixtures, especially mixtures of oats and 
barlew 

BRIEFER ARTICLES. 
ON NAMING VARIETIES. 

E. G. MONTC.OMKRY. 
(Read before the American Society of Agronomy, November 9, 1914.) 

In connection with the wheat survey made in New York the 
past summer, some interesting matters have come up in regard to the 
fate of variety names in the hands of the public. 

One very interesting case was found in western New York, where 
we frequently found that " No. 6 " was attached to the name of what 
we took to be at first several different varieties of wheat. For ex- 
ample, there was No. 6,'' International No. 6," " Rochester No. 6," 
" Clawson's No. 6," " Michigan No. 6," " Rural New Yorker No. 6," 
and " No. 16." Head samples were collected of all these varieties for 
comparison and they appeared to be the same thing, which led us to 
believe that this long list of names had a common origin. A little 
investigation suggested, at least, how some of the names arose. For 
example, it was found that about thirty years ago the International 
Seed Company, of Rochester, N. Y., had put out a variety called " No. 
6." This w^ould account for the first three names on the list. It is 
not as clear how the other names came into existence, but probably 
in the case of ''Michigan No. 6" the wheat might have been sold in 
Michigan and then brought back from that State by some farmer. 
Clawson's No. 6 is probably the correct name, as Garrett Clawson put 
several varieties on the market. At any rate, wie have evidence that 
the old name " No. 6 " or " International No. 6," as I believe it was 
called at first, has been construed in a number of ways. 

This brings up the question of whether it would not be desirable to 
take some steps for straightening out the nomenclature of our farm 
crops. I referred to this matter at the Columbus meetings of this 
Society as a result of some studies with a collection of oat samples 
secured principally from the seedsmen and experiment stations of the 



30 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

country. More than 400 named varieties of oats were secured but it 
was found that even at the experiment stations they were sometimes 
calling different varieties by the same name. It would seem that the 
time is at hand when if we are to attach any importance to names of 
varieties, at least some effort should be made to establish a standard 
naming system. This, I think, is of especial importance now, when 
so many of our experiment stations are beginning to put out new selec- 
tions of old standard types and have very often used a number system, 
such as " Minnesota No. 23 " or Wisconsin No. 10 " to designate a 
new strain. One question which should be discussed at this time is 
whether the number system or naming system is the safest. Not only 
are numbers in danger of being attached to various common names as 
more and more new varieties come out from the different experiment 
stations under numbers, but as these new selections begin to cross 
State lines, it seems to me in time there will be considerable confusion. 

If an official register of varieties could be started and maintained it 
would serve a useful purpose. This register might be on the plan of 
the herd books put out by the various live stock breeders' associa- 
tions. If all the named varieties could be associated in such a book 
with some description as to their character, adaptation and whatever 
history we have regarding their origin, it would be of great service. 
How little most of us know about the origin of our common varieties 
of farm crops. For example, those who have been in agronomic work 
for twelve or fifteen years can recall when Swedish Select oats or 
Kherson oats were introduced, but how many young men who have 
come into the field in the last five years know anything about Swedish 
Select or Kherson, how or when they were introduced, or know how 
to find this out. If we had something on our shelves compared with 
the herd book, it would be possible when we wanted to secure infor- 
mation about a particular variety, to take down the book and turn to 
what is known about it, and would certainly be a useful and valuable 
source of information. This would also serve to keep history straight 
regarding the new selected strains being put out by the plant breeders. 
For example, I doubt if many would know the origin of Wisconsin 
No. 10 oats or Minnesota No. 23 corn. It would be useful if this 
could be put in a permanent record so that we might know that in the 
one case it is a selection of Swedish Select and in the other case a 
selection of White Cap corn. I simply cite these as examples. Most 
of us have not time to trace out information of this kind even though 
it is of importance, but would make use of it if it was easily and 
readily available, as it should be. I do not know where such a registry 



i!Uii:i-i:u AIM ici.KS. 



31 



oiii^lit to 1)0 starlfd. perhaps it roiild he taken on as a part of the 
work ol' the Anieiiran Society of Agronomy, opening; a hook for 
each of the principal crops, and the list occasionally puhlished. 

1 am i)resenlin54- the matter at this time, more to stimulate discussion 
of the ([ucstion, especially on the two ])oints of whether we should not 
adopt a namini;- system rather than a numbering system, owing to less 
confusion of names, and whether it would be desirable and useful to 
have a registry for information about all known varieties as well as 
new varieties as they are introduced. If the matter might be dis- 
cussed through the columns of the Journal during the coming year it 
is possible that our committee on varietal nomenclature might take the 
matter up and have some definite recommendation to make by the 
time of our next annual meeting. — Cornell University, Ithaca, N. Y. 

MOISTURE RELATION OF TEXAS SOILS. 

G. S. FRAPS. 

(Read before the American Society of Agronomy, November 10, 1914.) 

The object of this paper is to present briefly some of the important 
results of the moisture studies carried on by the Chemical Division 
of the Texas Experiment Station. The apparatus used in this work 
consists of 48 galvanized iron cans, 12" in diameter and 24" deep, pro- 
vided with a block tin outlet at the bottom. These cans are embedded 
in the soil, and arranged in such a way that the water which percolates 
may be caught in glass bottles. Eight soils were used, there being six 
pots of each soil subjected to six different treatments. The data is 
from three years' experiments. 

Relation of Soil Type to Percolation. 

The eight soils may be divided in two groups, one consisting of four 
clays and clay loams and the other consisting of four sands and sandy 
loams. The average percolation from the uncultivated pots of the 
sandy loam group for three years is 6.36 inches, while the percolation 
from the clay and clay loam group is 12,72 inches; thus, the average 
percolation from the clay and clay loam group is double the 
quantity from the sand and sandy loam group. As all of the water 
which falls in these pots must either percolate or evaporate, it follows 
that the evaporation from the uncultivated clay soils is much less than 
from the uncultivated sandy soils. 



32 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Effects of Cultivation. 

One pot of each type was cultivated to the depth of two inches and 
another pot was cultivated to the depth of three inches. The perco- 
lation from the sand and sandy loam soil group cultivated two inches 
is 9.94 inches for the three years, with 6.36 inches for the uncultivated 
pot. The pot cultivated to the depth of two inches in the clay series 
percolated 12.22 inches compared with 12.72 inches for the uncul- 
tivated. 

This brings out a very striking fact, namely, that the sands and 
sandy loam soils had their moisture content conserved by cultivation 
two inches in depth, whereas, in the case of the clays and clay loams, 
the cultivation was of little effect. The three-inch cultivation gave 
slightly less percolation with the sands and sandy loams and slightly 
more percolation with the clays and clay loams, indicating the neces- 
sity for a deeper cultivation with the heavy soils. 

Effects of Potash Salts and Manure. 

Addition of sulphate of potash to the sandy soils caused a slight 
increase in percolation. With the clays and clay loam soils, the sul- 
phate of potash caused a decided decrease in percolation. The effect 
of the potash on the latter soils was to cause them to run together, 
decrease the penetration of water, and increase the evaporation. 

The application of manure to the different soils resulted in a de- 
cided increased percolation with the sands and sandy loams, the gain 
being 2.15 inches. A slightly increased precolation resulted with the 
clays and clay loams. With almost all the soils, the fall application 
of manure was more beneficial than the spring application. 

Details of this work will be published in full in bulletins of the 
Texas Experiment Station. 

Conclusion. 

The most striking point brought out in this work is the fact that the 
clays and clay loams show little appreciable saving of moisture due to 
the cultivation or the application of manure under Texas conditions. 
There is very little more percolation from the pots which have been 
cultivated or which have received the manure than from the bare 
uncultivated pots. 

On the other hand, the sands and sandy loam soils showed a de- 
cided gain in moisture by the use of cultivation and the use of manure. 
Both cultivation and manure increased the percolation from the pots, 



I!Rii;i i;k aim u tjcs. 



iiulicalini; a decreased eN'aporal i( 1 1 miisl l)e reinenibered dial dicsc 
rOvSiills were >eeiired under avera.i;e 'I'exas e( mdilioiis. in wliiidi ratlier 
wet pericnls alternate witli loiij^- periods of dry weather. — Texas Ex- 
periment Station. C'oUei^e Station, Texas. 

RELATION OF CHEMICAL COMPOSITION TO SOIL FERTILITY. 

(Read before the American Society of Agronomy, November lo, 1914.) 

G. S. FRAPS. 

Tliree general methods are used for the purpose of studying soil 
fertility. The first method consists of field experiments, in which the 
same crop is grown with the addition of different fertilizers to differ- 
ent plots. Many of the difficulties occurring in this method of in- 
vestigation are well known. The size of the crop is influenced not 
only by the fertility of the soil, but also by weather conditions, the 
character and location of the subsoil, and the soil moisture. It is 
necessary, therefore, to conduct these experiments over a period of 
several years, and also to make arrangements for check plots to over- 
come inecjualities in the character of the soil. As pointed out in 
several papers published in the Proceedings of the American Society 
of Agronomy, these inequalities are sometimes very significant on soils 
apparently uniform in character. Differences in soil moisture in dif- 
ferent parts of the field may seriously affect not only fertilizer tests, 
but varietal tests and other field tests. The results of the field tests 
depend not only upon the inherent fertility of the soil, but also are 
affected by weather conditions, soil moisture, climatic conditions, 
depth and character of subsoil, distribution of soil moisture, surface 
irregularities which affect distribution of rain, and other influences. 
The soil fertility is not necessarily the primary controlling condition. 

The second method of experiment is by means of pot tests. In 
making pot tests, the soils are carefully prepared, placed in pots, and 
the crops grown under standard conditions with or without various 
fertilizer applications. The soils used in these tests are largely re- 
moved from the influence of the weather, soil inequalities, irregular 
distribution of moisture, depth and character of subsoil and similar 
influences. The results, therefore, depend to a larger extent upon the 
plant food of the soil. The physical character of the soil and moisture 
relations, however, are not entirely eliminated. Different soils are 
certainly different in physical character and these influence the growth 



34 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



of crops in pots. The manner in which bacteria develop also in- 
fluences the production of forms of nitrogen that the plant may take 
up. The controlling condition, therefore, is not entirely the differ- 
ences in plant food, but depends also upon physical character of the 
soil, bacteriological condition and the other chemical constituents of 
the soil. 

In applying the results secured by pot experiments to the field, it is 
difficult to estimate the differences in conditions which prevail, and to 
make allowances for the influence of the climatic conditions, character 
of subsoil, moisture conditions, etc., which prevail upon the soil in the 
field and not upon the soil in the pot. 

A soil which shows itself to be deficient in nitrogen in pot experi- 
ments is not necessarily deficient in nitrogen in the field. In the first 
place, under the more favorable pot conditions, the plant makes heavy 
demands upon the soil nitrogen. The quantity of nitrogen demanded 
by the crop growing in the pot may easily exceed the crop possibility 
of the soil in the field, which may be limited by weather or physical 
soil conditions to a greater extent than by plant food. The soil would 
then be deficient in the pot experiment but not deficient under field 
conditions, since the plant food would not be the controlling condition. 
For this reason, it is advisable to consider not only the relative growth 
of the plants in the pots with or without the fertilizing element, but 
also the total quantity of the growth produced, and in applying the 
results to the field, to estimate whether or not field conditions which 
prevail would permit such a maximum growth. In other words, one 
must consider all the controlling conditions, and decide whether the 
limiting condition is plant food or something else. 

The third method of judging the fertility of the soil is by means of 
chemical analysis. There are three chief different kinds of chemical 
analysis ; first, complete estimation of all the plant food constituents 
by strenuous chemical treatment ; second, determination of the plant 
food soluble in strong hydrochloric acid and third, determination of 
the plant food soluble in weak solvents. 

The first two methods of analysis are more closely related to the 
wearing qualities of the soil and its ability to persist in production 
under cultivation. There is room for scientific study of soils along 
these lines, as there is considerable variation in the interpretation 
placed upon the results of complete analyses, or analyses with strong 
solvents and, as far as I know, there has never been any thoroughly 
scientific basis offered for such interpretations. 

The estimation of the total nitrogen and the phosphoric acid and the 
potash soluble in fifth-normal nitric acid, which we will here term the 



nRii:i"i:R aim k i,i-:s. 



35 



active plant food, is a fairl>' ^ood basis for jndf^iii.i;- \\\v ininu-diatc 
deficiencies of the soil. 'I'lie averai^e of a lar.^e nnnd)c'r of pol experi- 
ments at tlie Texas l^xperinient Station shows tliat the active j)hos- 
phoric acid, the active potash and the total nitrogen are directly related 
to the soil deficiencies bronght out by the {slant's f]jrowth. There are 
considerable deviations from the avera.^es in the case of individnal 
soil, which are being- subjected to further study. Some of these devi- 
ations disappear when two or more successive cro])s are averaged. 
Very probably we will hnd soils or groups of soils which deviate 
widely. This method, however, is the best one we have at present 
for studying the relative deficiencies of soils by chemical methods and 
should serve as a basis for further work from which to draw more 
definite conclusions. 

For the purpose of comparison, and in order to bring out more 
clearly the relative deficiencies of the soil, we state the results in 
bushels of corn per acre based on a weight of two million pounds. 
Table i shows these standards of interpretation: 



Table i. — Standards of Interpretation of Soil Analysis. 



Phosphoric Acid. 


Nitrogen. 


Potash. 


Active Phosphoric 


Corn 


Total Nitrogen. 


Corn 


Active Potash. 


Corn 


Acid. 


Equivalent. 


Equivalent. 


Equivalent. 


P.p.m. 


Bu. 


% 


Bu. 


P.p.m. 


Bu. 


-10 


6 


.000-. 02 


8 


0-50 


29 


10. 1-20 


12 


.O2I-.O4 


13 


51-100 


37 


20.1-30 


18 


.041-. 06 


18 


IOI-150 


51 


30.1-40 


24 


.061-.O8 


23 


151-200 


80 


40.1-60 


30 


.O81-.IO 


28 


201-300 


120 


60.1-80 


35 


.I0I-.I2 


33 


301-400 


157 


80.I-IOO 


40 


.I2I-.I4 


38 


401-600 


182 


100. 1-200 


45 


.141-. 16 


43 


601-800 


207 


200.1-400 


50 


.161-.I8 


48 







The figures given are intended to show the relative deficiencies of 
the sail in plant food and not the quantity of corn which the soil 
should produce. The actual production must vary with soil location, 
climate, season, etc., as well as with the soil fertihty. The relation 
between the analysis and the field production must be studied in differ- 
ent sections of the country. We are making such study in Texas. 

The table is useful, first, to show the probable deficiencies of a soil 
subjected to chemical analysis. There will be deviations from this 
probability; they require further study. 

It is useful, second, in selecting soils for pot or field work, to test 
availability of fertilizers. We have found it useful indeed in this way. 



36 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



It is useful, third, as an aid in the systematic study of soil. fertility. 
By dividing the soils into groups, arranged according to their defi- 
ciency in the plant food to be studied, we can compare and study 
deviations further. 

We must use the same caution in applying these results to field 
conditions, that we use in applying the results of pot experiments. A 
soil is deficient in nitrogen if its corn possibility for nitrogen is 12 
bushels, and field conditions permit the production of 20 bushels, but 
the same soil is not deficient in nitrogen if field conditions permit the 
production of only 12 bushels. An application of nitrogenous fer- 
tilizers would not give results in the latter case unless the controlling 
field conditions were likewise improved. 

The results of this work show that undoubtly there is a relation 
between the active phosphoric acid, the active potash, the total nitrogen 
of the soil and the soil deficiencies as shown in pot experiments ; and 
it opens a way for more extended study of these chemical relations 
which are so important to scientific agriculture. — Texas Experiment 
Station, College Station, Texas. 

THE PRODUCTION OF CORN IN HAWAII. 

C. K. McClelland. 

Since corn thrives so well in the Mississippi Valley and in other 
parts of the temperate zone, many of us have come to consider it as 
strictly a temperate zone crop. Its tropical origin and its adaptability, 
however, as well as the good crops often obtained in the tropics, indi- 
cate that corn is also a tropical cereal. In particular, Hawaii, with its 
wide variations in soil, precipitation and elevation, offers some condi- 
tions that favor the production of good yields of corn. The corn belt 
of Hawaii lies on the leeward or dry sides of the islands, at an eleva- 
tion of from 3,000 to 5,500 feet. The area now planted to corn is 
not extensive, but it is gradually being increased as the demands of 
the crop become known and the need for stored feed becomes more 
urgent. 

There are two regions especially noted for the excellence of their 
yields and product, the Kula region of the island of Maui and the 
Waimea-Waikii region of the island of Hawaii. The former extends 
for some 20 miles on the south slopes of Haleakala, the vast extinct 
crater on the island of Maui, at elevations between 3,000 and 4,500 
feet ; the latter occupies a similar position on the slopes of the summit 



I?RIi:i'I".R AKTlcr.I'lS. 



37 



of :\raiina Koa on Hawaii, hnl cxUaids somewhat liij^licr (5,500 feet) 
tlian does llie Kula rei^ion. In llie upper portions of these heUs frost 
oecnrs. 

The rainfall al any point or in an\ yeai" is ca|)ricioiis ; the hi.^her 
sloi)es eut off the northeast trade winds and deprive the lands of any 
moisture from that source, so that the f^reater part of the rainfall 
comes from southerly winds or " kona " storms, which occur mostly 
during the winter months. The moisture from the occasional summer 
showers is small in amount, usually evaporating within a few hours 
after it falls, and it is not a factor in crop production. This means 
that the crop must be produced by the moisture stored in the soil dur- 
ing the rainy season. This effective rainfall varies greatly in amount 
from year to year, in some seasons being almost nothing but usually 
averaging from 20 to 30 inches. 

The soils of the two regions are very similar in nature. They 
differ from most Hawaiian soils in that they contain little clay but 
have large amounts of silt, in which respect, they are similar to the 
soils of the corn belt of the continental United States. The following 
analysis by W. P. Kelley shows the mechanical composition of a soil 
at Waimea: 

Per Cent. 



Organic matter and combined water' 25.83 

Gravel and coarse sand 1-64 

Fine sand 38-03 

Silt 16.22 

Fine silt 19-99 

Clay 2.05 



I am informed by Mr. A. W. Carter, the manager of Parker Ranch, 
that these soils produced from 35 to 40 bushels per acre in a season 
during which but 4 inches of rain fell, most of which was lost by 
evaporation. The silt and organic matter of these soils give them a 
large moisture-retaining capacity. The one great objection to them 
is that they blow easily and terrific storms of red dust are common 
during the late winter and spring months. 

In these belts, because of their elevation, corn is always planted in 
the spring. Dent corn, for the most part mixed white and yellow, 
with rather large ears and kernels, is commonly grown ; at the higher 
elevations an earlier variety of white dent with smaller ears and ker- 
nels is planted, the seasons here being shorter. Some attention is now 
being paid to the selection of seed upon the Parker ranch and they 
furnish almost the entire supply of home-grown, commercial seed. 



38 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

At lower elevations, and in fact almost anywhere in the islands 
below the altitudes given, regardless of soil or cHmate, it is possible to • 
produce corn, but there is much less certainty as to the result. At 
800 feet, a crop of 40 bushels has been produced at Kunia on the 
island of Oahu and one about equally as good at the same elevation 
on the island of Molokai, but these results were obtained only once 
out of several trials, the causes of failure being insects and drought, 
the soils not being so retentive of moisture as those previously men- 
tioned. 

At sea level and usually at the lower elevations, attacks by leaf 
hoppers at the beginning of the dry season are almost sure to result 
disastrously to the corn crop. For this reason, it is preferable to plant 
corn in such localities in the fall (November to January), so that the 
crop will be made by the time the dry weather -comes in late spring. 
When grown for the first time in isolated sections late-planted corn 
may or may not escape the depredations of the hoppers. Even early 
planting does not insure a crop, as the winds in January have been 
known to dry up the tassels and prevent pollination. The College of 
Hawaii has produced as much as 90 bushels per acre near Honolulu 
and the same year the experiment station cut test rows indicating a 
yield of 60 bushels per acre, but the following season neither succeeded 
in getting a crop for the reason just stated. It would seem, then, that 
the production of corn in Hawaii on any large scale will be confined 
to the higher elevations, although medium elevations on the windward 
sides are giving indications that they may also produce the crop. 

Heretofore almost the entire corn area has been harvested by shuck- 
ing in the field from the standing stalks, a smaller area being cut and 
shocked. Recently several silos have been erected, notably upon the 
Parker ranch, and the corn is being put up as silage and stored^ for 
emergency feed for dry seasons. The Hind, Raymond, Cornwell 
and possibly other ranches have also put up silos for this purpose. 
The Erehwon ranch on Maui and the Mokuleia ranch on Oahu are 
the only dairy farms having silos; the other dairies, being supplied 
with water for irrigation, have plenty of green feed at all seasons. — 
Georgia Experiment Station, Experiment, Ga. 



iu<ii:i-i:k akticijcs. 



39 



AGRONOMIC AFFAIRS. 
FOREWORD. 

With this issue, the editorship of the Journal passes into new 
hands. Five years ago, Mr. C. R. r)all became secretary of the 
American Society of Agronomy and began editing its pnbhcations. 
He collected the scattered papers presented during the preceding two 
years of the life of the society and published them in Volume I of the 
Proceedings. The next three volumes of Proceedings followed in 
orderly course. At the annual meeting in 191 2, it was decided to 
begin the issuance of a periodical publication under the name of 
" The Journal of the American Society of Agronomy." Under 
Mr. Ball's careful guidance this publication was successfully launched 
and brought through the trying second summer of its infancy. When 
it had become a strong and lusty youngster, he expressed a conviction 
that the editorial as well as the secretarial duties should be trans- 
ferred to other hands. It was therefore incumbent on the society to 
elect another secretary. When the writer was chosen to this position 
in November last, it was with the understanding that the duties of the 
secretary and the editor were to be divorced, in accordance with the 
recommendation of the Committee on Nominations. The Executive 
Committee, however, thought it best to have the secretary continue to 
act as editor of the Journal, and that arrangement will continue in 
-effect during the present year. 

• The new editor bespeaks the hearty cooperation and assistance of 
the membership of the society in the publication of the Journal. 
This publication is in a peculiar sense just what its subscribers (the 
members of the American Society of Agronomy) make it, for on them 
it is entirely dependent for the matter that appears within its covers. 
Articles on experimentation, research, instruction and demonstration 
in agronomy are urgently requested. Brief articles are particularly 
useful, while news notes regarding agronomists and their affairs are 
always appreciated. The Journal offers a prompt medium of publi- 
cation for announcements of new discoveries and methods and for pre- 
liminary statements of interesting results of experimentation. The 
promptness of its issuance, however, depends very largely on the 



40 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

supply of material which is available. The cooperation already ex- 
tended to the present editor augurs well for the future, and leads him 
to believe that the pleasures of his association with the membership of 
the society will go far toward preventing his dual duties from becom-, 
ing a burden. 

THE PROBLEM OF VARIETAL NAMES. 

The brief article by Professor Montgomery entitled " On Naming 
Varieties," which appears elsewhere in this number, brings up anew 
the question of the confusion of varietal names of our leading field 
crops. Closely allied with it is the meagerness of adequate descrip- 
tions and of historical data for even our most important varieties. 
The confusion of varietal names has been greatly increased in the 
last twenty or twenty-five years by the public clamor for new things, 
which has too often been met by the sending out of old varieties 
under new labels. Not a little of the chaos has been caused by 
agronomic workers themselves, who have distributed established 
varieties of cereals and other crops under State or Federal num- 
bers, sometimes with no reference to the true name of the variety. 
More recently, the confusion has been still further augmented by the 
distribution of selected strains under numbers, in some cases differ- 
ing from other series of numbers for the same crop only by the 
addition of such words as pedigreed " or selected." The report- 
ing of data from varietal tests without sufficient descriptions of the 
varieties to make identification possible and without information as 
to the sources from which the material was obtained has made cor- 
relation of these tests extremely difficult. 

To the writer, two remedies for this confusion seem feasible. 
These are: (i) The publication of adequate descriptions and his- 
torical statements when varietal data are published, or at least when 
a variety if first mentioned in the reports of varietal tests; and (2) 
the establishment by this Society of definite rules for varietal nomen- 
clature, such as are now in use by the American Pomological Associa- 
tion, with the publication of names and descriptions of both old and 
new varieties by the Society in some such form as that suggested 
by Professor Montgomery. Neither of these remedies alone will 
be effective, but the two working together should accomplish much 
good. The second should eventually, in large measure, alleviate the 
necessity for the first. Discussion of this subject, as suggested by 
Professor Montgomery, will be welcomed. 



ACUONOMIC A I- 1' A I U.S. 4 I 

MEMBERSHIP CHANGES. 

The nicnihrrsliip rcpoiicd in llic last issue was 3()7. Since that 
time, 1 meniher lias been lost hy doalh and 26 new nienihcrs have been 
added, niakini^- the present nienihership 422. The chanj:^es in the 
membership list and the chanj^ed addresses since the last issue are as 
follows : 

Nkw Mkmhers. 

Blkdsok, R. Page, Dept. Agron., Agricultural College, Manhattan, Kans. 

Carter, L. M., College of Agriculture, Athens, Ga. 

CuRREY, Hiram M., 953 Monroe St., Corvallis, Ore. 

Damon, S. C, Experiment Station, Kingston, R. I. 

Galbratth, a. J., Agricultural College, Guelph, Ontario, Canada. 

Gilbert, M. B., 406 So. 15th St., Corvallis, Ore. 

Kenney, Ralph, Dept. Agron., Agricultural College, Manhattan, Kans. 

LoHNis, F., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Martin, John H., Bellefourche Exp. Farm, Newell, S. Dak. 

New, T., 218 Delaware Ave., Ithaca, N. Y. 

Olsen, Jens, 239 North 8th St., Corvallis, Ore. 

OsBORN, L. W., Experiment Station, Fayetteville, Ark. 

Peterson, W. A., Northern Great Plains Field Sta., Mandan, N. Dak. 

Plummer, J. K., Experiment Station, Raleigh, N. C. 

Prttchard, Fred J., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Rice, Thos. D., Bureau Soils, U. S. Dept. Agr., Washington, D. C. 
Richey, F. D., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Scales, Freeman M., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Seamans, Arthur E., Akron Exp. Farm, Akron, Colo. 
Simmons, Geo. E., Dept. Agron., University of Maine, Orono, Maine. 
Smith, Herbert G., Experiment Farm, Tucumcari, N. Mex. 
Welch, J. S., Gooding Exp. Sta., Gooding, Idaho. 

Westover, H. L., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Will, George F., Bismarck, N. Dak. 

Wright, R. Claude, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Young, Y., 135 University Station, Urbana, 111. 

Members Deceased. 

Pettit, J. H. 

Addresses Changed. 

Abbott, J. B., College of Agriculture, Durham, N. H. 

Beaumont, A. B., 415 College Ave., Ithaca, N. Y. 

Hungerford, De F., College of Agriculture, Fayetteville, Ark. 

Klinck, L. S., University of British Columbia, Victoria, B. C, Canada. 

Moorhouse, L. a., Farm Management, U. S. Dept. Agr., Washington, D. C. 

Oakland, Irwin, 319 W. loth St., Sioux Falls, S. Dak. 

Robertson, A. D., Douglas, Ariz. 

SuDDATH, R. O., Rowan County Farm Life School, China Grove, N. C. 



42 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



NOTES AND NEWS. 

J. B. Abbott, formerly associate in soil improvement at the Indiana 
station, is now state leader of county agents in New Hampshire. 

Max F. Abell has been appointed an assistant in farm crops in Ohio 
State University. 

R. T. Burdick has been promoted to an assistant professorship in 
agronomy at the University of Vermont. 

H. N. Cobb and L. J. Obold have been appointed assistants in 
agronomy at the Pennsylvania college and station. 

DeForest Hungerford, for nearly four years instructor in soils in 
the college of agriculture, University of Minnesota, on January i 
became assistant professor of agronomy in the college of agriculture, 
University of Arkansas. 

L. S. Klinck has been appointed dean of the College of Agriculture 
of the University of British Columbia at Victoria. He has been suc- 
ceeded as professor of cereal husbandry at Macdonald College of 
McGill University, Quebec, by James Murray, for several years super- 
intendent of the Dominion Experiment Farm at Brandon, Manitoba, 
and more recently the manager of large farming interests in Alberta. 

S. C. Jones, assistant professor of soil physics and assistant agron- 
omist of the Kentucky university and station, resigned November 15 
to become assistant in soils at the Indiana station. 

C. E. Leighty of the office of cereal investigations, U. S. Department 
of Agriculture, was recently elected treasurer of the Washington 
Botanical Society to fill a vacancy. C. E. Chambliss of the same office 
is secretary of the society. 

George Livingston, acting head of the department of agronomy in 
Ohio State University, is the author of a text-book of 424 pages for 
secondary schools entitled " Field Crop Production." 

George B. Mortimer has been appointed instructor in agronomy in 
the University of Wisconsin. 

C. E. Neff has been appointed an assistant in farm crops at the 
University of Missouri. 

Dr. James H. Pettit, since 1901 connected with the University of 
Illinois and for the past several years professbr of soil fertility in the 
college of agriculture and chief of soil fertility investigations in the 
Illinois station, died December 30, 1914, at Pasadena, Cal., where he 



ACUONOiM IC AIM AIUS. 43 

had gone in tlic ln)|)c of Ijcncfitinfj his hi ahli. I )r. rcUit was born at 
Lagrange, X. in 1S75; received his l^aehelor's degree at Cornell 
University in k/h). and his doctor's degree from the University of 
Gottingen in \^)0(). lie had l)cen a nicniher of the American Society 
of Agronomy since i()io. 

H. J. Patterson has resigned as president of the Maryland Agricul- 
tural College, eflective July I, 191 5. In accordance with his recom- 
mendation, the office of president will be abolished and the duties will 
be performed by a commission consisting of a director of college 
work, the director of the station and the director of extension. Dr. 
I^atterson will continue to be director of the experiment station. 

E. D. Sanderson, dean and director of the West Virginia college 
and station, has resigned efifective September 1, 191 5. It is reported 
that he will pursue graduate studies. 

S. H. Starr and E. C. Westbrook have been appointed assistants in 
agronomy in the Georgia State College of Agriculture. 

R. O. Suddath, who has been engaged in farmers' cooperative de- 
monstration work in Albemarle, N. C, for several months, is now 
instructor in agriculture in the Rowan County Farm Life School at 
China Grove, N. C. 

J. K. Wilson, formerly an instructor in botany in Cornell Univer- 
• sity, has been appointed an assistant professor of soil technology in 
the same institution. 

The department of agronomy of the Missouri university and station 
has been divided into departments of soils and farm crops, with M. F. 
Miller in charge of the former and C. B. Hutchinson in charge of the 
latter. 

. The department of soil technology of Cornell University moved 
into its new building during January. The department now has 
laboratories which are specially well equipped and has more space 
than was formerly available. Tw^o doctorate degrees were conferred 
by the department in January. Those who received these degrees, 
.with the titles of their theses, were J. K. Plummer, " Effect of Carbon 
Pioxid and Oxygen on Ammonification and Nitrification of Soils," 
and M. A. Klein, " Studies in the Drying of Soils." 

Willet M. Hays, who spent the year after his retirement as as- 
sistant secretary of the U. S. Department of Agriculture in Argentina 
as adviser to the government in developing plans for agricultural 
education, is again located at Washington, D. C. He is engaged in 
agricultural efficiency work and announces that he is prepared to 
serve business and public institutions in need of advice on agricultural 
matters. 



44 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY, 



J. K. Plummer, who, as noted elsewhere, recently received his 
doctorate degree from Cornell University, is soil chemist at the 
North Carolina station. 

Dr. H. L. Shantz, of the U. S. Department of Agriculture, de- 
livered a lecture on " The Natural Vegetation and Agriculture of the 
Great Plains and the Great Basin," before the Geographic Society of 
Chicago, on February 26. 

Association Meetings. 

At the annual meeting of the Society for the Promotion of Agri- 
cultural Science held in Washington, D. C, in November, 1914, L. A. 
Clinton of the U. S. Department of Agriculture was elected secre- 
tary to succeed Dr. E. W. Allen. President H. J. Waters of the 
Kansas State Agricultural College was reelected president of the 
society. 

The American Genetic Association, at its annual meeting in Wash- 
ington, D. C, January 12, 191 5, reelected all of its officers whose terms 
had expired. These included David Fairchild, president ; W. E. 
Castle, vice-president ; George M. Rommel, secretary ; Corcoran Thorn, 
treasurer; and Alexander Graham Bell, W. E. Castle, and Bleecker 
van Wagenen, members of the council. The address of the associa- 
tion is 511 Eleventh St. N. W., Washington, D. C. 

The Association of American Agricultural Colleges and Experiment 
Stations, at its meeting in Washington, D. C, on November 11-13, 
1914, elected the following officers : President, E. A. Bryan of Wash- 
ington ; vice-presidents, J. H. Worst of North Dakota, T. F. Hunt of 
California, C. D. Woods of Maine, P. H. Rolfs of Florida, and C. A. 
Lory of Colorado; secretary-treasurer, J. L. Hills of Vermont, and 
bibliographer, A. C. True of Washington, D. C. The executive com- 
mittee for the coming year are W. O. Thompson of Ohio, chairman; 
H. J. Waters, Kansas ; Brown Ayres, Tennessee ; W. H. Jordan, New 
York ; and H. L. Russell, Wisconsin. 

The fourth annual meeting of the American Society of Milling and 
Baking Technology was held at Washington, D. C, Nov. 18, 1914. 
Reports were made of experiments with baking powders by Dr. T. J. 
Bryan ; on analytical tests by B. R. Jacobs ; on collaboration in milling 
by L. A. Fitz ; and on methods of baking by C. H. Bailey. The fol- 
lowing officers were elected : President, R. Harcourt of the Ontario 
College of Agriculture; vice-president, R. W. Thatcher of the Minne- 
sota College of Agriculture; and secretary, J. A. LeClerc of the U. S. 
Department of Agriculture. 

The first meeting of Section M, Agriculture, of the American 



A(;k()N()Mic ai-i ains. 45 

Association for the Adv.imriiKMit of Science, was lu-ld at I'liila- 
(lcli)lna, J)occnil)cr 30. H)i |. I he vicc-prcsidcntial address of the 
section was delivered by I'rofessor L. II. liailey, liis subject l)einj^ 
" 'J'hc riace of Jvesearch and of I'uhlicily in the i^'orthconiin^ Country 
Life l)evel()i)nient." 'J'he other ])a])ers of the nieetinj^ were on the 
<]^eneral topic of rural economics, these hein^" presented hy /Assistant 
Secretary of .Agriculture Vroonian, Prof. (j. N. l.aunian of ( "ornell 
University, Dr. T. N. Carver of Harvard University, and Mr. ("has. 
J. lirand of the h\Mleral Office of Markets and Rural Organization. 
]^ean K. Davenport of the University of Illinois was elected vice- 
president and chairman of the section for the ensuing year ; Dr. A. C. 
True of the Office of Experiment Stations was chosen member of the 
General Committee of the Association; Dr. W. A. Taylor of the 
Bureau of Plant Industry, member of the council ; and President 
Kenyon L. Butterfield of Massachusetts, a member of the sectional 
committee (for five years). 

During the week of August 2-7, 191 5, as noted elsewhere under 
" Coming Events," the American Association for the Advancement of 
Science and its affiliated societies will meet in San Francisco, Cal. 
Among the affiliated societies are the American Genetic Association 
and several others less closely connected with agronomy. There will 
be a series of addresses on agriculture during the week, particularly 
on problems of food supply and of agricultural conservation. The 
following week, the Association of American Agricultural Colleges 
and Experiment Stations will meet at Berkeley, on the campus of the 
University of California. In connection with this meeting, numerous 
other agricultural organizations will hold their annual sessions, in- 
cluding the American Society of Agronomy. It is probable that this 
Society will meet on August 9 and 10. 

Changes in the Department of Agriculture. 

In accordance with the authorization given him by the agricultural 
appropriation act for the fiscal year ending June 30, 191 5, the Secre- 
tary of Agriculture, in submitting the estimates to Congress for the 
fiscal year ending June 30, 191 6, makes provision for the reorganiza- 
tion of certain lines of work in the Department of Agriculture. This 
authorization was requested by the Secretary in the interests of effi- 
ciency and flexibility. Among the changes recommended by the Sec- 
retary of Agriculture in his annual report for 1914 and included in the 
appropriation act now before Congress, those of special interest to 
agronomists include: The consolidation of the work in irrigation and 



46 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



drainage now in the Office of Experiment Stations and of rural archi- 
tecture in the Bureau of Plant Industry with the present Office of 
Public Roads under the new title of " Office of Public Roads and 
Rural Engineering ; " the union of the farmers' demonstration work, 
both north and south, with the Office of Experiment Stations under 
the new name of States Relations Service ; " the separation of the 
Office of Farm Management from the Bureau of Plant Industry, 
attaching it to the Office of the Secretary ; and the transfer of the soil- 
fertility investigations from the Bureau of Soils to the Bureau of 
Plant Industry. A number of other less important changes are 
planned. In addition, the regulatory, the research and the extension 
activities within the various bureaus are to be segregated so far as 
possible, without changes in the bureau organization. 

Reports of Local Sections. 

Annual Report of the Kansas Section. — Secretary C. C. Cunning- 
ham of the local section of the American Society of Agronomy at the 
Kansas State Agricultural College reports that the section meets 
monthly during the college year. At each meeting, two papers are 
presented on subjects of agronomic interest. These papers usually 
report the results of recent experiments at the Kansas station. The 
membership of the section is twenty-one. 

Annual Report of the Washington {D. C.) Section. — The Wash- 
ington section of the American Society of Agronomy was organized 
December 10, 191 3. Four meetings were held during the winter of 
19 1 3-14, at which the average attendance was 44. The membership 
of the section was 71, of whom 45 were members of the American 
Society of Agronomy. At the four meetings, a total of 14 papers 
were read ; in the discussion of these papers a large number of the 
members participated. 

Meeting of the Washington Section on Dec. 18. — The fifth regular 
meeting of the Washington section was held at the Cosmos Club 
December 18, 1914. Mr. H. N. Vinall presented a paper entitled 
" Natural and Artificial Hybrids of Sorghum and Johnson Grass," in 
which the peculiarities of root, stem and leaf growth of these hybrids 
were discussed. Some which have the free stooling habits and rapid 
growth of the Johnson grass but lack the perennial root stocks which 
make that grass a pest promise to become valuable forage crops. Mr. 
P. H. Dorsett, who was a member of the agricultural exploration 
party sent to Brazil in 1914 by the Department of Agriculture, talked 
on " Some Phases of Brazilian Agriculture." He gave much interest- 



yXCKONOM If A I'l' A I KS. 47 

Iii.l;" ill forniatioti on the forage, <^rain, fruit and coffee crops of lirazil. 
r.otli papers were illustrated and were followed by some discussion. 
At the business meeting-, officers for the cnsuini^- year were elected as 
t"oll()ws: Tresident. II. N. Vinall ; vice-i)resi(lent, C. K. Lei^dity ; secre- 
tary-treasurer, r. \'. C ardon ; and additional members of the execu- 
tive committee. J. C. Thysell and y\. C. Dillnian. 

Meeting of the W^ashiuyton Section on Jan. jo. — The sixth regular 
meetiui^ of the Washington section was held at the Cosmos Club Jan- 
uary 20, i()i5. The following program was presented: 

Comparative Effect of Cultural and CHmatic b^actors in Crop Pro- 
duction on the Great Plains, by W. W. Burr. 

Grain Crop Mixtures, by C. W. Warburton. 

Agriculture of the Peruvian Andes, by H. V. Harlan. 

Mr. Burr presented data from the records of numerous experiments 
conducted by the Office of Dry-Land Agriculture with spring wheat 
and oats in the Great Plains w^hich indicated strongly that climatic 
conditions had far more effect on crop yields than had been obtained 
from various tillage methods. This fact was particularly evident on 
soils with slight capacity for the storage of moisture. Mr. Warbur- 
ton's paper is presented elsewhere in this issue. Mr. Harlan talked 
very interestingly of his experiences of a year ago w^hen he investi- 
gated the agricultural possibilities of the Titicaca highlands in Peru for 
a syndicate of English land-holders there. His talk was illustrated 
with a number of lantern view^s from photographs taken during his 
visit. The evening closed with a social hour with refreshments. 

COMING EVENTS. 

Under this caption it is proposed to keep standing a schedule of 
coming meetings of various organizations more or less closely con- 
nected with agronomy. Secretaries of such bodies are invited to 
furnish information regarding their meetings. 

American Society of Agronomy. 

Special meeting, Mandan, N. Dak., July 14-16, 191 5, in connection 
with the meetings of the Great Plains Cooperative Association. 

Annual meeting, University of California, Berkeley, Cal., August 
9-10, 191 5. (In connection with meeting of Assoc. Agric. Coll. and 
Exp. Stations.) 

American Association for the Advancement of Science. 
San Francisco, Cal., August 2-7, 191 5. 



48 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

American Association of Agricultural College Editors. 
Madison, Wis., June, 191 5. 

American Genetic Association. 
San Francisco, Cal., August 2-5, 191 5. 

Association of Agricultural Colleges and Experiment 

Stations. 

Universit}' of California, Berkeley, Cal., August 11-13, 191 5- 

Great Plains Cooperative Association. 
Mandan, N. Dak., July 14-16, 191 5. 

LOCAL SECTIONS. 

Cornell University and Experiment Station. 

President, Millard A. Klein. 
Secretary, . 

Kansas Agricultural College and Experiment Station. 

President, W. M. Jardine. 
Secretary-Treasurer, C. C. Cunningham. 

Washington, D. C. 

President, H. N. Vinall. 
Secretary-Treasurer, P. V. Cardon. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. 7. March-April, 1915. No. 2. 



STUDIES IN THE DRYING OF SOILS/ 

Millard A. Klein, 
Cornell University, Ithaca, N. Y. 

(Contribution from the Department of Soil Technology, Cornell University.) 

CONTENTS. 

Page 



Introduction 50 

Review of Literature 50 

Experiment i, the Effect of Previous Drying of the Soil to Different 

Moisture Contents on Plant Food in the Soil and Plant Growth 54. 

Soils Used 54 

Method of Experimentation 55 

Effect of Previous Moisture Content on Plant Growth 56 

Effect of the Previous Moisture Content on the Morphological Char- 
acters of Wheat 56 

Effect of Previous Moisture Content on Crop Yield 58 

Effect of Previous Moisture Content on Total Nitrogen in the Crop ... 60 
Effect of Previous Moisture Content on Certain Constituents in the 

Water Soluble Matter in the Soil 61 

Total Solids 61 

Nitrates 62 

Potassium, Calcium, and Phosphorus 6-|. 

Lime Requirements > 66 

Summary 66 

Experiment 2, the Effect of Drying a Soil on its Physiological Con- 
dition AS Measured by the Carbon Dioxid Production and Nitri- 
fication 67 

Carbon Dioxid Produced on Drying and Wetting a Soil 67 

The Effect of Drying and Wetting a Soil on the Nitrates and Nitri- 
fying Pow^r 69 

Summary 71 

Discussion and Conclusions 72 

Bibliography 75 



i.A thesis submitted to the faculty of the Graduate School of Cornell Univer- 
sity in partial fulfillment of the requirements for the degree of Doctor of Phi- 
losophy by Millard Alschuler ]K4ein, B.Sc. Ithaca, N. Y., February, 1915. Re- 
ceived for publication March 2, 1915. 



49 



50 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Introduction. 

The drying of the soil by exposure to intense sunHght for some 
time has been made use of in certain arid regions of India to increase 
its productiveness. Since the drying of the soil in an arid region has 
a stimulating effect on crop growth, it is to be expected that the lower- 
ing of the moisture content in soils of the more humid regions, during 
seasonable changes, will influence their productiveness. The drying of 
the soil is a process that depends entirely on the climatic conditions, the 
degree and duration depending on the amount and distribution of 
the rainfall in the region concerned. In a study of the increased pro- 
ductiveness due to drying it will be necessary to consider the changes 
in the physical, chemical, and biological conditions of the soil. 

The change in the physical condition of the soil due to drying may 
be easily observed in the field. A better tilth is obtained as shown by 
an increased granulation. This increased granulation is to a great ex- 
tent due to the flocculation of the colloidal material. 

The changes in the chemical composition due to drying have been 
studied by many investigators in relation to the amount of plant food 
recoverable when a sample has been previously dried, under various 
conditions and temperatures. Great differences in the amount of plant 
food recovered have been observed when a sample has been previously 
dried, which would show that the drying of the soil in the field may 
greatly influence the chemical composition. In the last decade much 
attention has been given to the biological changes which are taking 
place in the soil. In this connection drying has been considered as a 
partial sterilization, as the results have been similar to those obtained 
from a partial sterilization with steam or antiseptics. 

The great importance of the biological factors cannot be ignored in 
the study of the drying of the soil, but at the present status of soil 
investigation they must be studied in connection with the biochemical 
changes produced. 

It is the purpose of the investigation to study the effect of drying a 
soil on crop yield and its correlation with certain chemical and phys- 
iological changes taking place in the soil. 

Reviev^ of Literature. 

The successive drying and wetting of a soil greatly affects its phys- 
ical condition. These processes cause an increased granulation, re- 
ducing the size of the granules and forming lines of weakness and 
cracks. In many ways this process is observed in the field but little 
data have been obtained experimentally showing the effect of succes- 
sive drying and wetting upon the physical condition. 



kl.ll\: SIIDII'.S I .\ llll'. DRVINC nii" S(.)II.S. 



.51 



Wollny (i8()7)-' stmlicd the clTcct of dryinj^ and wettiiij]; a soil on 
the voUime chanj^e. 'I'hc results sliow that a (lecrcase in vf)liini(' is 
obtaitietl by dryini^ and wcttinjj^. 

Cameron and dallat^hcr (1908) have shown that by repeated drying 
and wetting of a soil a i)oint is reached where the volume on con- 
traction due to drying is ec|nal to the expansion on wetting. This con- 
dition they call a " natural packing" of the soil. 

Fippin ( 1910) measured the effect of a repeated wetting and drying 
on clay soil by the force necessary to cause penetration. This force 
is reduced one half by five dryings and to one third l)y twenty dryings, 
granulation being increased 60 ])ercent. 

The effect of drying a soil has long been a problem to the soil chem- 
ist. Warington (1882) recognized the importance of drying a soil 
on the nitrate content. He found a reduction of nitrates in an oven- 
dried sample, a greater reduction when slowly oven-dried and an 
increase when air-dried. He advises drying a sample in a room, at 
55°-6o° F., for twenty-four hours as he found very little nitrification 
taking place at this temperature. 

Richter (1896) dried a garden soil in an oven at 100° C, and found 
an increase in the absorptive power for water and an increase in the 
nitrogen and soluble organic matter. 

The investigations of King (1905) on the amounts of plant food 
recoverable from field soils gives us the most valuable data on this 
subject. King compared the amounts of plant food recovered from 
fresh soil, soil air-dried, and soil dried in an oven at 110° C. He 
found more nitrates, phosphates, sulfates, bicarbonates, and silica, 
but less chlorides, recoverable from an oven-dried than from the fresh 
sample. The increase was greater than by was'hing the fresh sample 
with five times its weight in water. He considers that the increase 
may be partly due to the releasing of the salts locked up in the organic 
matter. Another cause may be what he calls the " fixing " power of 
soil grains, causing a concentration near the surface of the soil par- 
ticles which when dried are covered with the residues of evaporation 
and allow a greater solution than in the fresh soil. He also considers 
that the granular condition of the soil w^ould allow a large amount of 
water to be carried within the granules, the subsequent drying bringing 
the salts to the surface and making them more accessible to solution. 

Leather (1912) found an increase in the nitrates in soils that 'had 
been dried in the sun at Pusa, India, the increase being four times as 
great as in the fresh sample. 

Kelley and McGeorge (1913) studied the effect of drying on the 
2 Dates in parentheses refer to bibliography at end of paper. 



52 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



mineral constituents of Hawaiian soils. On the average, drying the 
soils at 1 00° C. increased the water-soluble carbonates, phosphates, 
manganese, calcium, magnesium, potassium, aluminum, sulphates, 
and silica over the air-dried soil. They consider that the causes in- 
volve many factors, both chemical and physical, as flocculation, de- 
hydration, oxidation, and the altering of the film pressure. 

Investigations have shown that drying a soil has an effect on its 
biological condition. These changes must be studied in relation to 
the chemical changes produced and may be considered biochemical. 
Early bacteriologists considered that the soil was merely sterilized 
when heated. In recent investigations soils heated to temperatures 
lower than 100° C. have been considered as partially sterilized. The 
drying of a soil may therefore be considered as a partial sterilization. 

Russell and Smith (1905) find that nitrifying organisms can be 
easily killed by an insufficient amount of moisture or by drying at 
100°' C. 

Rahn (1907) has made the most extensive investigations on the 
effect of drying soils on their physiological condition. From studies 
on carbon dioxid and acid production in sugar solutions and ammonia 
production in peptone solutions he finds a greater bacteriological ac- 
tivity in a soil previously dried at room temperature than in the same 
soil kept moist. Greater differences were found in a rich garden soil 
than in a sandy soil. The number of bacteria were decreased, and 
this he considers difficult to explain if the effect is on the bacterial 
activity. He believes that the effect can not be physical as an extract 
of the soil or a water suspension shows the same order of differences ; 
nor can it be the decomposition of the soil constituents because when 
phosphates and asparagin were added the same differences resulted. 
Mustard grew better on a soil previously dried. 

Pickering (1908) found that the heating of soils inhibited the ger- 
mination of certain seeds, and that the alteration of the soil began at 
temperatures as low as 30° C. No appreciable destruction of the 
detrimental substance occurred when the soil was kept for several 
months in a moderately dry condition. 

Further experiments by Pickering (1908) show an increase in the 
soluble organic material in soils heated to 30°, 60°, and 80° C. and 
then exposed to the air for two months at summer temperatures and 
watered occasionally. At higher temperatures a decrease was obtained. 

Russell and Hutchinson (1909) (1913) have studied the effect of 
partial sterilization by heating with steam. They find an increased 
availability in plant food and an increased plant growth. This they 
believe is related to a change in the bacterial flora, the larger phago- 



klkin: sruinios i.\ 'iiii; duving oi-' soils. 



53 



cytic organisms being killed and llic bcncllcial l)actcMia being allowed 
to increase. 

1 lowartl (1910) recognizes (his elTect in the soils which are exposed 
to the intense snnlight of India. The fertility is increased, and he 
believes that this may be dne to an inhibiting effect of partial steriliza- 
tion on the protozoa, as reported by Russell and Hutchinson on the 
studies of soils heated in the laboratory. 

Russell (1910) recognizes the observation made by Howard and 
believes that the soils exposed to sunlight may be dried and heated 
sufficiently to remove the factor which limits the productiveness of 
the soil. This is shown in further investigations by Russell and 
Hutchinson (1913). They exposed the soil to a temperature of 
35-38° C. for varying intervals. Upon remoistening the samples, it 
was found that the factor which is detrimental to the fertility is tem- 
porarily inhibited by ten days' drying. Soil exposed to sunlight for 
ten days behaves in the same manner. The detrimental organisms 
are killed at 55-60° C. and suffer considerably at lower tempera- 
tures (40° C). They conclude that drying a soil has the same effect 
as heating at low temperatures ; that is, it only temporarily eliminates 
the detrimental factor. 

Greig-Smith (1911) has shown that bacteriotoxins are destroyed 
at 94° C. He holds that upon remoistening the soil the more resist- 
ant bacteria multiply and become more numerous because of the ab- 
sence of bacteriotoxins. Sunlight and air-drying the soil destroy the 
toxins. 

Ritter (1912) made studies similar to those of Rahn and found 
that bacterial activity increased on drying a soil. A dried soil gave 
quicker and more intensive action. " Heavy " soil showed a greater 
difference than a light" soil. A repeated drying and wetting caused 
a decrease in the activity. He concludes that the physical condition of 
a soil goes hand in hand with the physiological condition. 

Fischer (1913) discusses the work of Rahn and Ritter and com- 
ments on their conclusions. He believes that more depends on the 
chemical composition than on the bacterial activity. Oxidation must 
be the principal factor, as the nitrates are increased on drying, yet the 
nitrifying organisms are killed. He thinks that colloids and surface 
tension must play an important part as a factor in this induced oxida- 
tion. 

Sharp (1913) studied the effect of drying by investigating soils that 
had been dried and kept in tightly stoppered bottles for thirty years. 
These soils still contained an average of 358,000 organisms per gram. 
Ammonifying organisms were present, but nitrification occurred only 



54 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



feebly in two of the nine soils examined. The nitrogen-fixing power 
was maintained but the Azotobacter forms were absent in all except 
one soil. He concludes that there is no relation between numbers and 
physiological efficiency. 

Russell and Petherbridge (1913) found that plants grown on soils 
heated to 55° C. show an acceleration in early growth succeeded by 
a steady growth. An increase in plant food in the soil and an in- 
crease in nitrogen, potassium, and phosphorus was found. 

Lyon and Bizzell (1913) found that the drying of the soil during 
seasonal moisture changes has both increased and decreased the 
nitrates, depending upon the kind of crop grown. In an unplanted 
plot an increase in soil moisture after a dry period has in most cases 
increased the nitrates in the soil. 

Experiment i. The Effect of a Previous Drying of the Soil to 
Different Moisture Contents on Plant Food in the 
Soil and Plant Growth. 

The object of the investigation is to study the effect of drying the 
soil on its chemical and biological condition and on plant growth. 
Previous investigations on the drying of the soil show that changes 
occur in the soil that greatly affect its fertility. That the effect is 
neither physical, chemical, nor biological, but a combination of the 
three, has been generally accepted. 

In the field the soil is continually being subjected to an intermittent 
wetting and drying. The length of drying and the moisture content 
depend upon the amount and variation of the rainfall in the region 
concerned. 

In a humid region the period of drying is short and the moisture 
content to which the soil is dried is usually not very low. In an 
arid region the soil is sometimes air-dry or nearly so and remains dry 
for some length of time. 

With this in view the plan of the experiment was to determine under 
controlled conditions the effect of drying the soil to different moisture 
contents on plant food in the soil and on plant growth. 

Soils Used. 

Two soils were used in the experiment, differing only in organic 
matter. Soil No. i is a heavy clay loam known as Dunkirk clay loam. 
It contains comparatively little organic matter, but the fertility is 
good. Soil No. 2 is the same type of soil, but the organic matter had 
been greatly increased by piling up timothy sod and allowing it to 



KLEIN: sTui)ii':s IN Tin-: dryinc. of soir.s. 55 

decompose. Some of llie Dii^^aiiir matter had not entirely decc^mijoscd. 
This caused some chflicnliN in prcparinj^f the soil for the pots, as the 
undecomposed ori^^anic mat lei" would tend to mass toj:jether. 

MctJiod of I'l.vpcvimcntation. 

The two soils were broui^lu in from the field December 9, igi i, thor- 
oughly mixed and put in 3-gallon pots, liach i)ot contained 1 1 kilo- 
grams of wet soil. A moisture determination was made at this time 
and the .pots were brought to complete saturation (40 per cent). All 
pots were removed to the field-house January 11, 1912. On February 
28, 1912, the pots were brought in from the field-house. While the 
pots were in the field-house the soil was frozen and a number of them 
were broken. The remaining pots were then allowed to dry in the 
greenhouse until they reached their permanent moisture content, as 
shown in Table i. 



Table i. — The Moisture Content of Pots Used in the Experiment. 





Soil No. I. 




Soil No. 2. 


Series r, Unplanted. 


Series 2, Planted 
at 25 Percent. 


Series i, U 


nplanted. 


Series 2, Planted 
at 25 Percent. 


Pot No. 


Moisture 
Content. 


Pot No. 


Moisture 
Content. 


Pot No. 


Moisture 
Content. 


Pot No. 


Moisture 
Content. 




Percent. 




Percent. 




Percent. 




Percent. 


421 


15 


401 


15 


447 


15 


431 


15 


422 


15 


403 


15 


448 


15 


432 


15 


424 


20 


408 


15 


449 


IS 


433 


15 


425 


20 


411 


20 


450 


20 


434 


20 


426 


25 


412 


20 


451 


20 


435 


20 


427 


25 


430 


20 


452 


20 


436 


20 


428 


30 


415 


25 


453 


25 


437 


25 


429 


30 


416 


25 


454 


25 


438 


25 






417 


2.S 


455 


25 


439 


25 






418 


30 


456 


30 


440 


3.0 






419 


30 


457 


30 


441 


30 






420 


30 


458 


30 


442 


30 










459 


40 


443 


40 










460 


40 


444 


40 














445 


40 



The pots of the highest water content were at saturation. In soil 
No. I the highest water content was at 35 percent, but after a few 
months the water stood on the surface of the soil and it became neces- 
sary to drop this water content to 30 percent. Just the opposite con- 
dition was found in soil No. 2, and the highest water content of 35 
percent was raised to 40 percent. The moisture content as shown in 
Table i gives this corrected percentage for the pots kept at saturation. 

The pots were kept at the different moisture contents as shown in 



56 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Table i until December 19, 1912. They were then divided in two 
series. One series was prepared for planting by bringing all pots to 
25 percent moisture content, while the second series was kept bare 
at the different moisture contents. The division of the pots in two 
series is shown in Table i. 

On January 14, 1913, all pots of series i were planted to Galgalos 
wheat. Forty seeds were planted in each pot. A good germination 
was secured and the seedlings were thinned to 12 plants. 

Effect of Previous Moisture Content on Plant Growth. 

At an early stage soil No. i allowed a better growth. On April 29, 
1913, the pots that had been previously held at a high moisture con- 
tent showed a poorer growth than those held at a low moisture con- 
tent. At the time oi heading the plants in pots 440, 441, and 442 
were much smaller than others of the same series. On June 4, the 
plants in pots 437, 438, and 439 were making the best growth. 

On May 22, it could be seen that the drying out of a soil to a low 
moisture content previous to planting was having a beneficial effect 
on plant growth. In soil No. 2 the pots which had been held at 30 
percent moisture content previous to planting showed a poorer growth 
than the ones previously held at 40 percent. 

A more luxuriant growth was obtained on soil 2, the great dif- 
ference evidently being due to the greater amount of organic matter 
in soil No. 2 or to some factor depending upon the organic content. 

On June 17, the plants were fully headed but were not entirely ripe. 
It was necessary to harvest on this date, however, owing to attacks 
made upon the plants by rodents in the greenhouse. The plants on 
soil No. I were somewhat nearer maturity than those on Soil No. 2. 
The plants from all pots were hung in the greenhouse and allowed to 
ripen completely. 

Millet was immediately planted, but a very poor growth of the 
seedlings was obtained. It was therefore replaced by buckwheat. 

The pots containing soil No. i had become so compact that it was 
necessary to lower the water content from 25 percent to 22 percent. 
During the growth of the buckwheat little difference could be ob- 
served. It was evident that the pots had reached a point where the 
previous moisture content had little effect, or that buckwheat was not 
appreciably affected by changes in the moisture content. 

Effect of Previous Moisture Content on the Morpholoyy of Wheat. 

A study of the effect of drying a soil to different moisture contents 
on the morphology of wheat is shown in Table 2. The results with 



KF.i'iN': s'iri)ii:s i x iiii". Dinrxc of soils. 



57 



soil No. 1 do iu)l show a j^rcal (lilTcrcMU-f in the lir.sl llirct' water 
contents (15. jo. and J5 i)ercent). A i;real derreasc will be noted in 
pots 41S, 4i(). and 4J0 in the nnnd)er of enlnis per i)ot, bnt only a 
slight difference in the other characters. These ])ots were held at 
satnration before planting; and a poor physical condition of the soil 
was n()ticeal)le. 



Table J. — Effect of Prcrious M oislurL- Content on the M orphological Characters 

of Wheat. . 



Pre- ^ , 
vious ' Culms 
Pot No.' Moist- 1 per pot 
lure Con-' , 
1 tent, i Plants). 


Length of 
Culm. 


Length of 
Head. 


Grains 


Empty , Spike- 
Spike- lets with 

iGrTn. 


Spike- 
lets with 

two 
Grains. 


Spike- 
lets 
(Total.) 


Nodes 

per 
Culm . 



Soil No. I 





P. ct. 




Inches 


Inches 














401 


15 


25 


34-7 


3-08 


16.8 


2.8 


7.2 


4.8 




4.0 


403 


15 


25 


34.7 


3-00 


13-4 


3-4 


7.0 


4.0 




3-7 


408 




25 


37-3 


3-30 


16.5 


2.7 


6.0 


5-2 




3-3 


Ave. 




25 


35.6 


3-12 


16.0 


3-0 


6.7 


4-7 


14.4 


3-7 


411 


20 


26 


33-5 


3.20 


15-4 


2.3 


7.1 


4.2 




3-9 


412 


20 


20 


42.5 


3-20 


17.0 


2.4 


6.5 


5-1 




4.0 


430 


20 


26 


36.6 


3-20 


16.3 


3-1 


7.0 


4.8 




3-9 


Ave. 


20 


24 


37-5 


3.20 


16.0 


2.6 


6.8 


4-7 


14.1 


3-9 


415 


25 


25 


34-8 


2.80 


14.7 


2.5 


7.0 


4.1 




4.0 


416 


25 


22 


35-3 


3.00 


13-8 


3-0 


7-1 


3.3 




3.6 


417 


25 


19 


34-0 


2.80 


13-0 


3-0 


7.0 


3-2 




3.6 


Ave. 


25 


22 


34-7 


2.95 


14.0 


2.8 


7.0 


3.5 


13-3 


3-7 


418 


30 


12 


31-3 


2.40 


10.5 


3-3 


6.3 


2.0 




4.0 


419 


30 


13 


34-5 


2.50 


12.0 


2.9 


6.1 


3-0 




3.7 


420 


30 


13 


31.6 


2.45 


10.3 


1.6 


6.3 


2.2 




3-5 


Ave. 


30 


13 


35.8 


2.45 


II. 


2.5 


6.2 


2.4 


II. I 


3-7 



Soil No. 2 



431 


15 


36 


30.5 


3.36 


19.0 


2.6 


5-4 


6.4 




3-4 


432 


15 


34 


30.3 


3-50 


18.3 


2.4 


6.0 


6.3 




3-5 


433 


15 


44 


34-4 


3-40 


17.0 


2.5 


5-3 


5.8 




3-5 


Ave. 


15 


38 


31-7 


3-40 


18. 1 


2.5 


5.6 


6.2 


14-3 


3-5 


434 


20 


30 


28.5 


3.20 


14. 1 


2.2 


5-2 


6.0 




3-7 


435 


20 


34 


29.6 


3.20 


16.8 


2.2 


5-5 


5-5 




3-5 


436 


20 


34 


30.0 


3.60 


16.9 


2.0 


5-0 


7.3^ 




3-5 


Ave. 


20 


33 


29.4 


3-30 


15-9 


2.1 


5-2 


6.3 


13.6 


3.6 


437 


25 


33 


32.4 


3-6o 


18.6 


2.0 


5-2 


6.6 




3-7 


438 


25 


35 


30.6 


3-40 


18.5 


2.0 


6.0 


6.3 




3.6 


439 


25 


27 


34.3 


3-40 


16.6 


1.7 


5-2 


6.5 




3.9 


Ave. 


25 


32 


32.4 


3-50 


17.9 


1.9 


5.5 


6.5 


13-9 


3.7 


440 


30 


17 


34.2. 


3-40 


17.7 


2.1 


4.0 


6.72 




3.6 


441 


30 


17 


- 23.2 


2.50 


13.0 


2.3 


4.4 


4.4 




3-2 


442 


30 


13 


22.7 


2.30 


9.0 


3-5 


5-0 


2.0 




3-0 


Ave. 


30 


16 


26.7 


2.70 


13-2 


2.6 


4-5 


4.4 


11.5 


3-3 


443 


40 


34 


27.7 


3.00 


14-5 


2.4 


6.5 


4.0 




3-3 


444 


40 


41 


30.0 


3-10 


18. 1 


2.7 


6.2 


6.0 




3-7 


445 


40 


41 


30.3 


3-40 


16.8 


3-2 


6.2 


5.2 




3-5 


Ave. 


40 


38 


29-3 


3-20 


16.8 


2.8 


6.3 


5-1 


14.2 


3-5 



1 Also 5 three-grained spikelets. 
- Also 7 three-grained spikelets. 



58 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

In soil No. 2, greater differences in the morphological characters 
due to the effect of the previous moisture content could be noted. 
Here, as in the plant growth, the soil that had been held at 30 per- 
cent moisture content shows the poorest results. There is a similarity 
between the pots which had been held at 15 percent and those at 40 
percent, the average number of culms per pot being as great in the 
40 percent as in the 15 percent pots. 

Comparing the two soils, we find a greater number of culms per pot 
in soil No. 2, but the length of culms is somewhat less in this soil. 
The greater number of spikelets w^ith one grain were found on the 
plants in soil No. i, and the greater number with two grains were 
found on the plants in soil No. 2. It will be seen that in soil No. i there 
was a decrease in the number of grains per head as the moisture 
content was increased, while in soil No. 2 there was little difference 
as affected by the different moisture contents. 

Effect of Previous Moisture Content on Crop Yield. 

A large number of investigators have studied the effect of different 
moisture contents on crop yield. They do not, however, consider the 
possible influence of the moisture condition of the soil before planting. 

In this investigation the soil was kept at the different moisture con- 
tents for ten months before planting. At the time of planting all pots 
were brought to an optimum water content and the weights recorded. 
During plant growth the pots were kept at this content by adding dis- 
tilled water every day and bringing the pots to standard weight. 
Under this plan any differences in the amount af dry matter produced 
in the crop must be due to the effect of the previous moisture con- 
tent and not to differences during the growth of the plants. 

As the two soils differ only in organic content, a comparison of the 
results should show the influence of organic matter on the factors 
effecting the previous drying out of a soil to various moisture contents. 
The effect of the previous conditions of soil moisture on the produc- 
tion of dry matter is shown in Table 3. 

In soil No. I, the greatest weight of dry matter in the first crop, 
both grain and straw, is found in the soil that had been previously 
dried to 15 percent, a somewhat smaller yield at 20 percent and at 
25 percent, and a decided decrease at 30 percent. The soil that was 
held at 30 percent was reduced to 25 percent at the time of planting. 
The same order of differences was found in soil No. 2, except that 
when 40 percent is reached there is a decided increase over the 30 
percent. In this series the soil that was held at 40 percent was re- 
duced to 25 percent at the time of drying. 



Ki i:i\: sri nii s i \ riii". nm iNC oi" snii.s. 



59 



In soil Xo. J, a iiioisliirc coiitcuL ol 40 percent must be compared 
to tlic content of 30 percent in soil No. 1, as in l)oth cases \vc have 
complete saturation for each soil. In the clay loam i)ots which had 
been previously held at saturation the yield of dry matter is smallest, 
but in the organic clay loam pots which had been held at saturation 
the ^■ield is as large as those with the lowest moisture content, ff 
we consider that the lc-)wcring of the moisture content in the pots at 
40 percent moisture content is an effective drying out previous to 
planting, there is decided im-rease due to drying just before ])lantiiig. 

Tai!1,e 3.— /:#(V/ of rmioiis Moisture Coiitciii on U'eiylil of Dry M alter of 
Wheat and Buckwheat Produced: 



Soil No. I. I Soil No. 2. 



Pot No. 


Previ- 
ous 

Mois 
ture 

tent. 


Wiicat. 
Grain. 1 Straw. 


Buck- 
wheat. 


Pot No. 


Previ- 
ous 

Mois- 
ture 

Con- 
tent. 


V.heat. 
Grain. j Straw. 


Piuck- 
\\ heat. 




P. Ct. 


Grams 


Grams 


Grams 




P. Ct. 


Grams 


Crams 


Grams 


401 


15 


18.2 


30.3 


5-9 


431 


15 


20.5 


42.3 


8.8 


403 


15 


17.4 


28.7 


4.5 


432 


15 


17.0 


39.0 


9.0 


408 


15 


19.1 


31-8 


4-7 


433 


15 


23.2 


45-7 


9.4 


Ave. 


15 


18.2 


30.3 


4-7 


Ave. 


15 


20.2 


42.3 


9.1 


411 


20 


18.5 


29-5 


4-5 


434 


20 


15.8 


30.6 


9.0 


412 


20 


I5.8' 


26.6 


4.9 


435 


20 


16.3 


34-5 


9.6 


430 


20 


20.0 


33-2 


4.0 


436 


20 


21.7 


42.5 


. 9-5 


Ave. 


20 


18. 1 


29.8 


4-5 


Ave. 


20 


17.8 


35-9 


9-3 


415 


25 


16.6 


27.0 


4.0 


437 


25 


15-8 


41.9 


9.9 


416 


25 


13.9 


25.1 


4.0 


438 


25 


16.8 


40.1 


10.8 


417 


25 


II. 4 


20.6 


5-5 


439 


25 


14.4 


33-9 


9.2 


Ave. 


25 


14.0 


24-3 


4-5 


Ave. 


25 


15-5 


38.6 


9.9 


418 


30 


4.9 


10. 




440 


30 


8.8 


22.1 


8.0 


419 


30 


5-2 


12.5 


6.2 


441 


30 


5-2 


II-3 


7-4 


420 


30 


6.3 


12.7 


6.3 


442 


30 


2.4 


7-7 


7.2 


Ave. 


30 


5-5 




6.3 


Ave. 


30 


5-5 


13-7 


7-5 












443 


40 


14.6 


28.6 


9.0 












444 


40 


22.9 


46.5 


10. 












445 


40 


20.2 


41.6 


10.8 












Ave. 


40 


19-3 


38.6 


9.9 



This, how-ever, is not the case in the 30 percent moisture content pots 
which have also been lowered to 25 percent before planting. 

The effect of drying to low^er moisture contents previous to planting 
has been to increase the crop yield, as is conclusively shown in soil 
No. I and also in soil No. 2, if the low^ering of the 40 percent moisture 
content before planting be so considered. 

With the second crop, buckwheat, there has been little effect. There 



60 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

is, however, a greater increase in the yield of soil No. 2 over soil No. 
I than in the first crop. 

Effect of Previous Moisture Content on the Total Nitrogen in the 

Crop. 

The results obtained in the determination of the total nitrogen in the 
dry matter of the grain and straw are shown in Table 4. It has been 
repeatedly shown that plants grown under different moisture condi- 
tions show a variation in the amount of plant constituents found in the 
dry matter. A greater crop growth usually causes a smaller percent- 
age of nitrogen in the plant. On the other hand, if the available 
nitrogen in the soil is increased by an increase in the moisture con- 
tent, an increase may be found in the percentage of nitrogen in the 
crop. The chemical constitution of the soil must be a factor, more 
especially in the soluble organic matter. 



Table 4. — Effect of Previous Moisture Content on Total Nitrogen in the Crop. 







S 


oil No 


. I. 








Soil No. 2. 


Pot No. 


Previous Mois- 
ture Content. 


Total Nitrogen. 


Pot No, 


Previous Mois- .j 
ture Content, j 


Total Nitrogen. 


Wheat. 


Buckwheat. 


Wheat. 


Buckwheat. 


Grain. 


Ratio. 


Straw. 


Ratio, j 


Total. 


Ratio. 


Grain. 


Ratio. 


i 

<A 


Ratio, j 


Total. 


Ratio, j 




Per- 


Per- 




Per- 




Pet- 






Per- 


Per- 




Per- 




Per- 






cent. 


cent. 




cent. 




cent. 






cent. 


cent. 




cent. 




cent. 




401 


15 


1.49 




.27 




1.63 




431 


15 


3.26 




1.02 




2.07 




403 


15 


1.68 




.26 




1.62 




432 


15 


3-30 




I-I3 




2.25 




408 


15 


1.60 




•25 








433 


15 


3.26 




1. 18 




1.84 




Ave. 


15 


1.59 


100 


.26 


100 


1.63 


100 


Ave. 


15 


3-27 


100 


I. II 


100 


2.05 


100 


411 


20 


1.73 




.26 




1.74 




434 


20 


3-24 




1. 17 




2.30 




412 


20 


1.60 




.26 




1.82 




435 


20 


3.25 




1. 16 




2.10 




430 


20 


1.48 




.29 




1. 81 




436 


20 


3.26 




•95 




2.04 




Ave. 


20 


1.60 


100 


.27 


103 


1.79 


109 


Ave. 


20 


3-25 


99 


1.09 


98 


2.15 


104 


415 


25 


1.63 




.26 








437 


25 


3-32 




1. 15 




2.09 




416 


25 


1.67 




.25 




1.45 




438 


25 


3-27 




1. 18 




2.15 




417 


25 


1.72 




.27 




1.62 




439 


25 


3-43 




1. 12 




2.18 




Ave. 


25 


1.67 


104 


.26 


100 


1-53 


94 


Ave. 


25 


3-34 


102 


1^15 


103 


2.14 


104 


418 


30 


1.88 


_ 


.30 




1.66 




440 


30 


3-o6 




1.60 




2.35 




419 


30 


1. 71 




•39 








441 


30 


2.88 




1.60 




2.40 




420 


30 


1-53 




.28 




1. 71 




442 


30 


3.26 




1.60 




2.42 




Ave. 


30 


1. 71 


107 


•32 


107 


1.68 


103 


Ave. 


30 


3-07 


93 


1.60 


145 


2.39 


116 


















443 


40 


3.36 




1.25 




2.22 




















444 


40 


3-31 




.88 




1.56 




















445 


40 


3-34 




.92 




1.49 — 


















Ave. 


40 


3-34 


102 


1. 01 


91 


1.46 71 



KLKIN : STUnilCS IX 11 1 1". I)KVIN(] OI' SOILS. 



6i 



The results presented in Table 4 show that there has been no effect 
on the nitrogen of the crop resulting from a difference of the previous 
moisture content. A comparison of the two soils shows on the aver- 
age twice as nnich nitrogen in the plants grown in the soil high in 
organic matter as in the same soil low in organic content. As these 
soils differ only in organic content and the results show practically no 
difference due to water content, the difference in the percentage of 
nitrogen in the dry matter nnist l)e caused through some factor due to 
the organic matter. 

Effect of Previous Moisture Content on Water Soluble Matter. 

It has been shown by a number of investigators that the complete 
drying of the soil causes an increase in the soluble salts recoverable 
from a water extract. However, in this investigation the soil has in no 
case been dried to an air-dry condition. 

The results presented in Table 3 show that a lowering of the mois- 
ture content previous to planting has caused an increase in the plant 
growth. In order to determine whether this increase was related to 
an increased amount of plant food, determinations were made on the 
total solids, nitrates, potassium, and calcium in the water extract and 
phosphorus in a fifth-normal acid extract. 

It might be expected that the greater plant growth in the soil high 
in organic matter would result from the large amount of plant food 
carried in the organic material. Water extracts were made from 
soils from all the pots immediately after the second crop was har- 
vested, by adding 500 c.c. of distilled water to 100 grams of the soil 
and filtering through a Pasteur-Chamberlain water filter. 

Total Solids. — Table 5 shows the results obtained in the determina- 
tion of the total solids from a water extraction of the soil sample. It 
will be seen from this table that low water content reduces the total 
solids in the unplanted clay loam, while in the planted series of this 
soil there is little difference in the results. The results with the soil 
high in organic matter show an increase in the total solids in both the 
planted and unplanted series with an increased moisture content. 

Considering the effect upon the clay loam, it is evident that drying 
the soil to a lower moisture content has increased the water-soluble 
matter. The planted series of this soil shows this same increase, 
although at the time of planting all pots were brought to the same 
moisture content. The opposite effect in the organic clay loam must 
be attributed to the greater amount of organic matter. It is evident 
that the lowering of the moisture content has had no effect on the total 
soHds recovered, as the amounts increase with the increased water 
content. 



62 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 5. — Effect of Previous Moisture Content on Soluble Salts in the Soil 
{Total Solids in Water Extract Expressed in Parts per Million). 



Soil No. I. 


Soil No. 2. 


Series i. Planted. 


Series 2, Unplan 


ted. 


Series i. Planted. 


Series 2, Unplanted. 




Ph 


Previous Mois- 
ture Content. 


Total Solids. 


Ratio. 


Pot No. 


Previous Mois- 
1 ture Content. 


Total Solids. 


Ratio. j 


Pot No. 


Previous Mois- 
ture Content. 


Total Solids. 


Ratio. 


Pot No. 1 


Previous Mois- 
ture Content. 


^" 

"0 

m 

p 


Ratio. 

1 


401 


T r 
J- J 














A'i. I 


T C 
^ J 


I 7 




AA7 


T [? 
■■•J 


1226 






T c 
D 






A2 1 


T < 


874 




All 


T tr 
■'• 


70A 




440 


T e 

J- J 


747 




408 


15 


402 





422 


IS 


800 





433 


15 


438 





449 


15 


1510 





Ave. 


15 


336 


100 


Ave. 


15 


837 


100 


Ave. 


15 


553 


100 


Ave. 


15 


1198 


100 


411 


20 


408 












434 


20 


915 


_ 










412 


20 


372 




424 


20 


890 




435 


20 


687 




451 


20 


882 




430 


20 


440 




425 


20 


690 




436 


20 


473 




452 


20 


2222 




Ave. 


20 


406 


120 


Ave. 


20 . 


790 


94 


Ave. 


20 


691 


124 


Ave. 


20 


1550 


131 


415 


25 


329 












437 


25 


760 




453 


25 


1613 




416 


25 


344 




426 


25 


666 




438 


25 


870 




454 


25 


1584 




417 


25 






427 


25 


464 




439 


25 


746 




455 


25 


1323 




Ave. 


25 


336 




Ave. 


25 


565 


67 


Ave. 


25 


792 




Ave. 


25 


1507, 


127 


418 


30 


366 


z 










440 


30 


941 




456 


30 


1456 




419 


30 


362 




428 


30 


523 




441 


30 


960 




457 


30 


1364 




420 


30 


320 




429 


30 


526 




442 


30 


605 




458 


30 


2352 




Ave. 


30 


350 


95 


Ave. 


30 


525 




Ave. 


30 


835 


151 


Ave. 


30 


1724 


146 


















443 


40 


741 




459 


40 


2450 




















445 


40 


938 




460 


40 


1467 




















Ave. 


40 


863 


156 


Av. 


40 


1808 


153 



. It would seem that the lowering of the water content as affecting 
the water-soluble matter depends entirely upon the types of soil used. 

Nitrates. — In order to ascertain what effect the lowering of the 
moisture content may have upon the nitrification in the soil, the nitrates 
were determined on samples from all the pots after the second crop 
had been harvested. The samples were brought to the laboratory 
and the moisture and nitrate determinations were made within sixteen 
hours after sampling. The nitrates were determined colorimetrically 
by the phenol disulphonic-acid method. The results are presented in 
Table 6. 

If a comparison of series i and 2 of both soils is made it will be 
seen that a reduction of the nitrates was caused by plant growth. The 
analyses also show that the nitrates are less in the planted series of 
soil No. I than in the same series of soil No. 2. This may be due 
to the greater amount of nitrates present in the organic clay loam be- 
fore planting, there being more than necessary to satisfy the require- 



Kua.N' : si i Dii'.s 1 .\ I III'. i)in'i\<i oi' son.; 



63 



nicnts of [he plaiil.^. Imoiii Tahlcs and .j it will be sl'cmi lliat a 
greater growth and a greater anionnl of total nitrogen in tlie crop 
were obtained in tbe organic clay loam. A derrea.se is fonnd in tbe 
nitrates of tbe planted series dne to tbe i)revions lowering of tbe 
moisture content, tbis decrease being more decisive in tbe clay loam, 
lender tbe unplanted scries of botb soils tbe results would tend to sbow 
tbat tbere bas been little effect on tbe nitrates due to a lowering of tbe 
moisture content. A reduction may be expected in tbe ])lanted series, 
as pots at tbe previous low moisture contents gave nmcb greater 
growtb. 

T.VBLE 6— Effect of Previous Mo-isturc Content on Nitrates in the Soil. 



Soil No. 



Series i. Planted. 



Series Unplanted. 



Pot No. 


Previous 
Moisture 
Content. 


Nitrates. 


Ratio. 


Pot No. ■ 


Previous 
Moisture 
Content, j 


Nitrates. 


Ratio. 


1 

Pot No. : 


Previous 
Moisture 
Content. 


Nitrates. 


Ratio. j 


! 

Pot No. 


Previous 1 

Moisture 

Content. 


Nitrates, j 


•£ 






p.p. 








p.p. 








p.p. 








p.p. 






Pxt. 


m. 






P.ct. 


m. 






P.ct. 


m. 






P.ct. 


m. 




401 


15 


14.0 




421 


15 


421 




431 


15 


204 




447 


15 


864 




403 


15 


22.0 




422 


15 


183 




432 


15 


140 




448 


15 


688 




408 


15 


21.3 












433 


15 


no 




449 


15 


502 




Ave. 


15 


19.0 


100 


Ave. 


15 


302 


100 


Ave. 


15 


151 


100 


Ave. 


15 


685 


100 


4.: 


20 


16.8 




424 


20 


341 




434 


20 


159 




450 


20 


1647 




412 


20 


26.4 




425 


20 


183 




435 


20 


222 




451 


20 


242 




430 


20 


54-9 












436 


20 


186 




452 


20 


801 




Ave. 


20 


32.7 


173 


Ave. 


20 


262 


87 


Ave. 


20 


182 


132 


Ave. 


20 


896 


131 


415 


25 


74-4 




426 


25 


496 




437 


25 


522 




453 


25 


697 




416 


25 


26.8 




427 


25 


130 




438 


25 


164 




454 


25 


485 




417 


25 


37-2 












439 


25 


244 




455 


25 


454 




Ave. 


25 


46.1 


242 


Ave. 


25 


313 


103 


Ave. 


25 


310 


205 


Ave. 


25 


545 


80 


418 


30 


78.0 




4.28 


30 


767 




440 


30 


405 




456 


30 


560 




419 


30 


61.5 




429 


30 


83 




441 


30 


193 




457 


30 


752 




420 


30 


26.4 












442 


30 


339 




458 


30 


432 




Ave. 


30 


55-3 


290 


Ave. 


30 


429 


134 


Ave. 


30 


312 


205 


Ave. 


30 


581 


85 


















443 


40 


372 




459 


40 


760 




















444 


40 






460 


40 


752 




















445 


40 


185 




























Ave.l 40 


278 


184 


Ave. 


40 


756 


no 



Soil No. 2 
Series i, Planted. 



Series 2, Unplanted. 



Why the lowering of the moisture content in the unplanted series 
had no effect is hard to explain^ as an aeration of the soil under the. 
low water content would be expected to increase the nitrates, yet it is 
evident that the results, are influenced by other factors which tend to 
equalize this effect. 

It was thought that a study of the nitrate-producing power of the 



64 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

soil might throw some Hght on the effect of drying soil on the nitrify- 
ing organisms of the soil. At the time the nitrates were determined 
in the soil, another lOO-gram sample was taken, placed in a bottle, 
plugged with cotton, and incubated for seven days at 30° C. Nitrate 
determinations were then made as shown in Table 7. 

A comparison of the nitrates in the soil as shown in Table 6 with 
the nitrates after incubation as shown in Table 7 will show that in 
nearly all cases denitrification has taken place. It can be seen from 
the tables that the variation in the samples from pots under the same 
treatment are too great to warrant any conclusions on the effect of 
lowering the moisture content on the power of the nitrifying organisms 
of the soil. 

Table 7. — Effect of Previous Moisture Content on Nitrates Produced by Incu- 
bation for Seven Days at 30° C. 



Soil No. I. 



Series i, Planted. 



Series 2, Unplanted. 



1 Pot No. 


Previous Mois- 
ture Content. 


Nitrates. 


Ratio. 


Pot No. 


Previous Mois- 
ture Content. 


Nitrates. 


1 

Ratio, j 


Pot No. 


Previous Mois- 
ture Content 


Nitrates. 


Ratio. 1 


Pot No. 


Previous Mois- 
ture Content. 


Nitrates. 


Ratio. 




p. 


p. p. 






P. 


p. p. 






P. 


p. p. 






P. 


p. p. 






ct. 


m. 






Ct. 


m. 






Ct. 


m. 






Ct. 


m. 




401 


15 


39 




421 


15 


240 




431 


15 


124 




447 


15 


433 




403 


15 


64 




422 


15 






432 


15 


144 




448 


15 


672 




408 


15 


56 












433 


15 


88 




449 


15 


672 





Ave. 


15 


53 


100 


Ave. 




240 


100 


Ave. 


15 


118 


100 


Ave. 


15 


593 


100 


411 


20 


59 




424 


20 


222 




434 


20 


264 




450 


20 


1152 




412 


20 


48 




425 


20 


184 




435 


20 


176 




451 


20 


370 




430 


20 


34 












436 


20 


96 




452 


20 


704 




Ave. 


20 


47 


89 


Ave. 


20 


203 


84 


Ave. 


20 


178 


153 


Ave. 


20 


778 


131 


415 


25 


37 




426 


25 


200 




437 ■ 


25 


200 




453 


25 


608 




416 


25 


34 




427 


25 


160 




438 


25 


144 




454 


25 


576 




417 


25 


40 












439 


25 


168 




455 


25 


336 




Ave. 


25 


37 


70 


Ave. 


25 


180 


75 


Ave. 


25 


171 


145 


Ave. 


25 


507 


85 


418 


30 


50 




428 


30 


21 




440 


30 


352 




456 


30 


480 




419 


30 


34 




429 


30 


84 




441 


30 






457 


30 


572 




420 


30 


50 












442 


30 


360 




458 


30 


448 




Ave. 


30 


44 


83 


Ave. 


30 


52 


20 


Ave. 


30 


329 


278 


Ave. 


30 


500 


84 


















443 


40 


144 




459 


40 


528 




















444 


40 






460 


40 


526 




















445 


40 


152 




























Ave. 


40 


148 


125 


Ave. 


40 


527 


89 



Soil No. 2. 



Series i, Planted. 



Series 2, Unplanted. 



Potassium^ Calcium, and Phosphorus. — Determinations were made 
of the potassium and calcium in the water extracts and of the phos- 



KLEIN: STUnil'.S IN TlIK DRYINC DF SOILS. 



65 



Taiujc 8. — Effect of rrcrions Moisture Content on the rotassinin, Calcutni and 
Phosphorus in the Soil. 





Series i 


, Planted. 




Series a, Unplanted. 




Previous 








Previous 


1 






Lime 


Pot No. 


Moisture 


K. 


Ca. 


I Pot. No. 


Moisture 


K. 


Ca. 




Required 




Content. 








Content. 








(CaO). 


Soil No. i 






p.p.tn. 


p. p.m. 






p. p.m. 


p. p.m. 




p p m 


401 


15 


42.2 


9.0 


421 


15 


12.0 


18.5 






403 


15 


21.3 


12.2 


422 


15 


43-1 


21.4 


13-7 




408 


T C 

J 


12.6 


JO. I 














Ave. 


15 


23 -3 


10.4 


Ave. 


15 


27-5 


20.0 


— 




411 


20 


30.4 


7-3 


424 


20 


14.7 


21.5 







412 


20 


21. 1 


13-6 


425 


20 


41.8 


25-4 


131 




430 


20 


II. 7 


II. 8 














Ave. 


20 


21. 1 


10.9 


Ave. 


20 


27.6 


23-4 


— 


C! 


415 


25 


21.3 


9-7 


426 


25 


16.4 


20.3 







416 


25 


II.6 


12. 1 


427 


25 


20.3 


18.8 


14.6 




417 


25 


26.4 


8.6 














Ave. 


25 


19.8 


10. 1 


Ave. 


25 


18.3 


19.6 


— 




418 


30 


24.4 


— 


428 


30 


12.7 


22.0 


— 




419 


30 


21.4 


14.6 


429 


30 


32.3 


12.6 


15.0 




420 


30 


22.2 


8.4 














Ave. 


30 


23-7 


11.4 


Ave. 


30 


22.5 


17-3 


— 












Soil 


No. 2 










431 


15 


28.3 


I3-I 


447 


15 


74-4 


23.2 


14-3 


1,400 


432 


15 


19.2 


17.6 


448 


15 


84.2 


27.1 




— 


433 


15 


62.2 


9.9 


449 


15 


60.0 


29.6 


— 





Ave. 


15 


36.6 


13-5 


Ave. 


15 


72.6 


26.6 


— 





434 


20 


38.4 


19.0 


450 


20 


144-3 


32.7 


13.4 


1,100 


435 


20 


29.6 


I5-I 


451 


20 


84.4 


18.6 






436 


20 


34-3 


14.6 


452 


20 


55.8 


32.3 






Ave. 


20 


34-1 


16.2 


Ave. 


20 


91-5 


27.9 






437 


25 


14.6 


17-3 


453 


25 


104.0 


27.5 


18.1 


1.275 


438 


25 


29.0 


13-4 


454 


25 


41.6 


19.8 






439 


25 


38.1 


20.3 


455 


25 


111.3 


25.0 






Ave. 


25 


27.2 


17.0 


Ave. 


25 


85.6 


24.0 






440 


30 


45-2 


21.0 


456 


30 


112. 


22.8 


' II. 8 


1,200 


441 


30 


61.0 


17.2 


457 


30 


61.8 


25-9 







442 


30 


41.4 


22.8 


458 


30 




24.9 






Ave. 


30 


49.2 


20.0 


Ave. 


30 


86.9 


24-5 






443 


40 


22.9 


19.4 


459 


40 


96.6 


24.8 


15-2 


1.075 


444 


40 


105.2 


13.4 


460 


40 


79.0 


27.0 






445 


40 


9.2 


12.3 














Ave. 


40 


46.4 


I5-0 


Ave. 


40 


87.8 


25-9 







phorus in a fifth-normal nitric acid extraction of the soils. The cal- 
cium was determined by the turbidity method and the potassium by 
the colorimetric method of the Bureau of Soils.^ The phosphorus 

3 Schreiner, Oswald, and Failyer, George H., Colorimetric, Turbidity and 
Filtration Methods Used in Soil Investigations, U. S. Dept. Agr., Bur. Soils 
Bui. No. 31, 1906. 



66 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



was determined colorimetrically according to the method of Fraps.* 
The results are shown in Table 8. 

From a study of Table 8 it may be seen that there has been very 
little effect due to the different moisture contents. A reduction of 
the potassium and the calcium was found in the planted series of 
soil No. 2. " The phosphorus was determined in the unplanted series 
of both soils and no differences were found due to differences of 
moisture content. 

It must be concluded from these data that the reduction of the 
moisture content has no appreciable effect on the potassium, calcium, 
and phosphorus in the soil. 

Lime Requirement. — In order to determine whether the lowering 
of the moisture content had any effect on soil acidity, lime requirement 
determinations were made according to the method of Bizzell.^ These 
results are presented in Table 8. The clay loam shows no lime re- 
quirement, the organic clay loam an average of 1,200 p. p.m. CaO. 
No differences are shown due to the lowering of the moisture content. 

Summary of Experiment i. 

1. The drying of soil previous to planting has a beneficial effect on 
plant growth. 

2. The factor which causes this beneficial condition due to drying 
is affected by the organic matter in the soil, as is shown from the 
results of the two soils used, which differ only in organic content. 

3. The previous drying of the soil has no effect on the total nitrogen 
in the dry matter of the crop. 

4. The water-soluble matter is increased in the clay loam with a 
drying out of the soil, while in the same soil with a high organic con- 
tent the opposite result occurs. The organic content must be the de- 
ciding factor. 

5. In the planted series of both soils a decrease in the previous mois- 
ture content has resulted in a decrease in the nitrates in the soil. In 
the unplanted series no effect has been found. 

A denitrification was found in the soil samples when incubated at 
30° C. for seven days. The great variation in the test allows no con- 
clusions from the effects of drying the soil. 

6. The drying out of the soil has little effect on the available potas- 
sium, calcium, or phosphorus in the soil. 

4 Fraps, G. S., Active Phosphoric Acid and Its Relations to the Needs of 
the Soil for Phosphoric Acid in Pot Experiments, Tex. Agr. Exp. Sta. Bui. 
No. 126, 1909 (1910). 

5 Bizzell, J. A., and Lyon, T. L., Estimation of the Lime Requirements of 
Soils, Journ. Indus. Engin. Chem., 5: 1011-1012, 1913. 



KLi^iN: srri)ii:s ix 'iiii'. Din'ixc oi' soils. 



E.\ri:ui M i:nt 2. Tin-: Iu'M-ik r oi- Duvinc a Soil on its Physioi.oc;- 
icAL Condition as Mi:AsrRi:n wv 111 C'auuon Dioxid 

I 'konrC'I'lOX AM) X I I KI I' ICA'I ION. 

As a stud}' of tlic olTcct of drying- and \\cltin,<^- a soil on its l)actcrial 
activity, the caii)on dioxid formation has l)ccn determined. A study 
of the effect on nitrification has also heen made hy determining the 
nitrates in the soil and its nilrifyini( power. It has been shown by 
previous investigators that the bacterial activity of the soil may be 
measured by the carbon dioxid production. It can not be said that 
this determination gives a complete measurement of the bacterial ac- 
tivity, yet sufficient data have been obtained to show that the effect of 
drying a soil on its bacterial activity may be determined in this way. 
As a check on the carbon dioxid determination and because of the 
importance of the nitrifying organisms, the nitrates and the nitrifying 
power were determined. 

When the pots that had been kept in the field-house for two months 
were returned to the greenhouse, it was found that a number of them 
had been broken. The clay loam (soil No. i) from six of these 
broken pots was transferred to new pots, and the soil brought to an 
optimum moisture content. 

After the pots were held at an optimum moisture content for four- 
teen months, they were submitted to a treatment as shown in the 
following plan : 

Pot I. Original soil. Determinations made on wet soil. 

Pot 2. The soil taken from the pot and dried in the drying room at 30-35° C. 
for ten days and determinations made on the dry soil. 

Pot 3. Soil dried as above, but it was again brought to an optimum water con- 
tent (25 per cent.) and held for sixteen days before determinations 
w^ere made. 

Pot 4. Treated as pot 3, but held thirty-five days before determinations were 
made. 

Pot. 5. Treated as pot 4, but again dried and held eleven days at optimum 
moisture content before making determinations. (Two dryings.) 

Pot 6. Treated as pot 5, but again dried and wet again fourteen days before 
making determinations. (Three dryings.) 

Carbon Dioxid Produced on Drying and Wetting a Soil. 

The method used to study the amount of carbon dioxid produced in 
a soil was a modification of Stoklasa.*^ A diagram and description 
of the apparatus is presented in figure 3. 

The soil sample was well mixed and 500 grams (on dry basis) 
placed in the glass cylinder. The cylinders were kept in an incubator, 

^ Stoklasa, J., in Handbuch der Biochemischen Arbeitsmethoden (Alber- 
halden), Band 5, Teil 2, p. 869, 1912. 



68 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

held at a temperature of 30° C. The air free of carbon dioxid was 
drawn through the soil in the cylinders, the rate of flow being regu- 
lated at k " on the aspirator. By making some preliminary experi- 
ments the maximum rate of flow necessary was found. The carbon 
dioxid produced was measured daily for ten days, except in the case 
of the air-dry soil, which ceased production after the seventh day. 
All determinations were made in triplicate. The results for each 
soil are presented in Table 9. 



Table 9. — Daily Production of Carbon Dioxid in Parts per Million from a Soil 
Variously Treated as to Moisture Content. 





Parts per Million of Carbon Dioxid. 


Sample N®. 


Day. 


Total. 




I 


2 3 1 4 5 


6 1 7 


8 9 


10 



Pot I. Original Soil— Not Dried. 



I 


546 


206 


76 


92 


120 


88 


52 


64 


198 


234 


1,676 




542 


216 


104 


104 


86 


162 




152 


92 


140 


1.598 


3 


546 


112 


116 


72 


74 


122 





204 


72 




1,318 


Average 


544 


178 


99 


90 


93 


124 


26 


140 


120 


187 


1,601 



Pot 2. Soil Dried and Not Wet Again. 



I 


108 


8 





68 


4 












_ 


188 


2 


84 


16 





46 


10 





32 









188 


3 


54 


108 


4 


40 


44 


30 


30 








310 


Average 


82 


44 


I 


51 


19 


10 


20 









229 




Pot 3 


. Soil Dried and Wet 


again for 


Sixteen Days. 




I 


396 


228 


174 


246 


158 


224 


276 


236 


164 


268 


2,370 


2 


328 


316 


184 


208 


58 


206 


294 




168 


158 


1,972 


3 


648 


104 


184 


232 


68 


220 


252 


96 


168 


188 


2,160 


Average 


457 


216 


181 


228 


94 


217 


274 


128 


166 


20s 


2,166 


Pot 4. 


Soil 


Dried and 


Wet again for Thirty-five Days. 




I 


486 


276 


216 


216 


240 


240 


132 


168 


24 





1,998 


2 


200 


220 


224 


186 


224 


162 


2 


62 


164 


124 


1,561 


3 


128 


244 


140 


156 


244 


178 





74 


142 


30 


1,336 


Average 


271 


247 


193 


186 


236 


193 


45 


lOI 


110 


53 


1,635 



Pot 5. Soil Dried Twice and Wet again for Eleven Days. 



I 


260 


554 


202 


168 


196 


166 


142 


166 






1.854 


2 


1112 


402 


374 


164 


682 


66 


196 


76 






3.072 


Average 


686 


478 


288 


166 


439 


116 


169 


121 






2,463 


Pot 6. 


Soil Dried Three Times and Wet again for Fourteen Days. 


I 


414 


296 


186 


6 


400 


160 


100 


152 


216 


276 


2,206 


2 


600 


284 


322 


262 


244 


204 


162 


no 


264 


190 


2,642 




507 


290 


254 


134 


322 


182 


131 


131 


243 


233 


2,427 



By a study of the tables it will be seen that the bacterial activity was 
greatly increased by a previous drying of the soil. In the soil that 



KMCiN : s'i ri)ii:s in riii': duvinc oi-' soils. 



was not wet a^ain al'U'r (lr\inj4, the l)actcrial activity was j^rcatly 
inliibitcil, ami alter sc\cn (la}s the carbon dioxid i)ro(hiction had com- 
pletely stopped. 

One drying of the soil greatly increases tlic activity over the orig- 
inal soil. In the soil held at an optinumi moistnre content for 35 
days after drying the production of carbon dioxid becomes normal 
again, as shown by a comparison of Pots i and 4 (Table ()). A soil 
dried twice does not show a much greater activity than when dried 
once, wdiile three dryings show no increase over two dryings. Iwi- 
dently the factor that causes the increase is not greatly affected after 
the first drying of the soil. 



The Effect of Drying and JVctting a Soil on the Nitrates and 
Nitrifying Poiver. 

The nitrates were determined colorimetrically in a water extract of 
the sample by the phenol disulphonic-acid method. Samples from each 
pot were taken at the time the carbon dioxid determination was made, 
one part being used for the immediate determination of the nitrates 
and the other for the determination of the nitrifying power. The 
nitrifying power was determined by incubating the samples for seven 
day at 30° C. The results are show^n in Table 10. 




Fig. 3. Apparatus for determination of the carbon dioxid produced in a soil. 
Description of apparatus: a. Incubator; h, wash-bottle containing Ba(0H)2; 
c, wash-bottle containing KOH ; d, glass cylinder containing soil ; e, U-tube 
containing H2SO4; /, U-tube containing CaCL ; g, potash bulb; h, U-tube con- 
taining CaCl2; i, U-tube containing H2SO4 ; aspirator bottle; k, stop-cock for 
regulating flow of air; t, thermometer; w, glass-wool in bottom of cylinder; 
3', thermostat. 



70 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Table io. — Effect of Drying and Wetting a Soil on the Nitrates and Nitrifying 



Power. 








Parts per Million of Nitrates 


n ; 






Sample No. 


Original 
Soil at 25 

Percent 
Moisture 

Content 

(Pot I). 


Soil Dried 
Ten Days. 
Dry Soil 
(Pot 2). 


Soil Dried 
Ten Days, 

Then 
Brought to 
25 Percent 
Moisture 
Content and 
Held for Six- 
teen Days 
(Pot 3). 


Soil Dried 
Ten Days, 

Then 
Brought to 
25 Percent 
iVJoisture 
Content and 
Held Thirty- 
five Days 
(Pot 4). 


Soil Treated 

as No. 4, 
Then Dried 
Ten Days, 
I'hen Wet 
Eleven Days 
(Pot 5). 


Soil Treated 
as No. 5. 

Then Dried 
the Third 
Time and 
Wet Four- 
teen Days 
(Pot 6). 


Nitrates in the Soil 




I 
2 

Ave. 


140 
160 

ISO 


143 
133 

138 1 


117 
117 
117 


166 
166 
166 


264 
256 
260 


328 
336 
332 



Nitrifying Power after Incubation for Seven Days at 30° C. 



Series i, 


Soil alone: 














I 


208 


183 


184 


136 


368 


400 




2 


200 


160 


162 


136 


384 


384 




Ave. 


204 


172 


172 


136 


376 


392 


Series 2, 


Soil +2 gr. dried blood: 












I 


192 


228 


208 


272 


400 


464 




2 


160 


200 


216 


336 


400 


432 




Ave. 


176 


214 


212 


304 


400 


448 


Series 3, 


Soil +0.5 gr. (NH4)2C03: 












I 


224 


190 


232 


288 


672 


416 




2 


208 


228 


224 


304 


640 


416 




Ave. 


216 


209 


228 


296 


656 


416 



First considering the effects on the nitrates, we find that the 
drying of the soil has greatly reduced them, and as has been prev- 
iously shown also has reduced the carbon dioxid production. The 
rew'Ctting of the dry soil for a period of sixteen days has further de- 
creased the nitrification. In this sample the opposite is found in the 
carbon dioxid production. In the soil held moist for thirty-five days 
after one drying and in those previously dried twice and three times, 
an increase in nitrification is found. This increase corresponds with 
the carbon dioxid production in these samples. Why sample 3 has 
shown a decrease is not altogether clear. 

The results from the nitrate determinations as compared with the 
carbon dioxid production show that the nitrification as effected by the 
drying of the soil is for the most part biological, but there must be 
factors other than biological which influence this change. These will 
be discussed later. 

The nitrifying power of the soil w^as determined in three series in 
order to observe the effect of the addition of organic and inorganic 



KMCIN : STl'Dll'lS IN' 1' 1 1 I'. DiniXC ()!•" SOILS. 



71 



nilroi^cn on niti-ilicalion. Samples of loo .grains ul' soil were ii>e(l in 
each case. I lie three series were as lollow s: 

Scries 1. Intrcatccl. 

Scries J. grams of dried blood added to the sample. 
Scries 3. 0.5 gram of (NH,)S()i added to the sample. 

It will he seen from Tahle 10 that the addition of nitrogen either in 
organic or inorganic form has increased the nitrification. However, 
the results from each treatment as compared with the nitrates he fore 
incubation show, in the main, the same order of difference. 

Considering the effect of drying of the soil on the nitrifying power, 
the original soil shows an increase of 54 p. p.m. when the soil has been 
incubated alone. Series 2 and 3 of the same sample gave an increase 
of 26 and 66 p. p.m. respectively. In the dry soil the nitrates are in- 
creased in about the same ratio, but here there is an error due to the 
wetting of the soil on incubation, and the same results are obtained as 
in sample 3. If the nitrifying power of the dry soil had been deter- 
mined, it is very probable that no nitrifying power would have been 
obtained. In sample 3 there was an increase of 55, 95, and 11 1 p. p.m. 
in series i, 2, and 3 respectively. This shows that the effect of prev- 
iously drying a soil is to increase the activity of the nitrifying organisms. 
In sample 4 the incubation of the soil has shown a decrease, but an 
increase of 138 and 130 p. p.m. was found in series 2 and 3 of this 
sample. In the carbon dioxid determination the rewetting of the 
soil for a period of thirty-five days gave a result similar to the orig- 
inal soil. Soils dried two and three times have increased the nitrify- 
ing power over the samples dried once. From the table it can be seen 
that the maximum is reached at two dryings. These results would 
show that the activity of the nitrifying organisms is increased by a 
previous drying of the soil, but reaches a maximum at tw^o dryings. 

Summary of Experiment 2. 

1. The bacterial activity as measured by the carbon dioxid produc- 
tion is increased by a previous drying of the soil. 

2. The carbon dioxid production is very low in a dry soil, the pro- 
duction ceasing after seven days. 

3. The activity is increased by two dryings, the third drying show- 
ing only very slight increase over the second. 

4. A soil held moist for thirty-five days after one drying assumes its 
normal condition, the activity being only slightly greater than in the 
original soil. 

5. The previous drying of the soil increases nitrification. 



72 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



6. The dry soil shows a reduction in nitrates, as in the carbon dioxid 
production. 

7. The nitrification is increased by two dryings and again in the 
soil dried three times. 

8. The nitrifying power of the soil is increased by a previous drying. 

9. The nitrifying power continues to increase with two dryings, 
but probably reaches its maximum at three dryings. 

10. The effect of adding organic or inorganic nitrogen to the 
samples is shown by a marked increase in the nitrates produced. The 
increase in the determinations is in the same ratio as in the sample 
with no nitrogen added. 

^Discussion and Conclusions. 

The foregoing results show that the drying of soil has an effect 
on its fertility, which results in an increased plant growth. The crop 
growth is increased by a previous lowering of the moisture content, 
but the difference in the organic content as shown in the two soils 
used, has influenced the changes which are produced. 

In Experiment i there is a drying out of the soil by a lowering 
of the moisture content, but in no case do we have a soil completely 
air-dried. This experiment represents a condition that takes place in 
a humid region where the soil rarely reaches an air-dry condition. In 
a consideration of the results from Experiment i this must be kept in 
mind. 

While the effects of drying on the physical changes have not been 
definitely studied, a discussion of the subject will necessarily include 
the physical factors which are acting through a change in the soil 
moisture. 

The drying out of the soil increases the granulation, which is in the 
most part due to an alteration of the colloidal material. The increased 
granulation allows a greater amount of soluble salts to be carried in 
the granules, which on subsequent wetting allows a greater amount to 
go into solution. Referring to the results obtained on the amounts of 
w^ater soluble material found in the two soils under different mois- 
ture contents, we find that the drying out of the clay loam has caused 
an increase in the water soluble material, while in the organic clay 
loam the opposite occurs. As these soils differ only in the organic 
content, the factor which influences the solubility of the soil constitu- 
ents must be due to the difference in the organic matter of the two 
soils. If in the clay loam a granulation due to drying has caused a 
greater alteration of the colloidal material, this would allow the water 
greater access to the soil particle ; and if the concentration of the salts 



klkin: studies in tiiI': dkvinc oi- soils. 



73 



on the siii-f;ico of (he parlirk" has rcsnllc-d from an increased lilni 
pressure around tlie i)arlicle, a j^realer amount of soluble material 
will be recovered by a subse(|uent wettinji^ of the soil. Ifovvever, in 
the orji^anic clay loam the decrease found in the soluble matter on 
dryin<^ would tend to show that the i^real amount of material soluble 
when the soil is held at hi^h water content overcomes any increase 
that may be due to a drying of the soil. 

Ai^ain, as the organic clay loam shows a lime re(|uirement of J ,200 
p. p.m. CaO, the acidity which is due to the organic matter would 
det^occulate the colloidal material, resulting in a less amount of surface 
being exposed to the solvent than in the clay loam. It has been 
shown by previous investigators that a soil high in organic matter has 
a great absorptive power. This absorptive power would increase the 
plant food held by the soil and result in an increase of the soluble 
matter when the soil was dried; but if the soil was not dried to a low 
enough w^ater content to alter this absorptive puower, no increase would 
result. The resinous and fatty material of the organic matter may 
surround the mineral particles and allow no greater solubility even if 
more soluble salts are exposed to the solvent after a drying of the soil. 
It has been considered by some investigators that the water-soluble 
material forms a colloidal film around the soil particle. On drying a 
soil this film will be altered and allow a greater solubility of the sol- 
uble salts. This may partly account for the increase in the 
water-soluble material in the clay loam when dried to a 15 percent 
moisture content, but in the organic clay loam it may be that the large 
amount of organic matter soluble would strengthen this colloidal film 
and a greater drying be necessary to alter the pressure of the film. 

Other factors, mainly chemical, must be considered in a discussion 
of the effects of drying soil. The dehydration of the silicates, deoxi- 
dation of the oxids, and oxidation of many of the compounds are some 
of the important chemical changes which take place in the soil on 
drying. However, in Experiment i the soil has not been dried below 
a moisture content of 15 percent, and these factors cannot exert any 
marked influence on the changes produced. 

The drying out of the soil causes an increase in the nitrification in 
the planted series, but no effect is observed in the unplanted series. 
Why this occurred is not clear. The biological factors that are at 
work here may sufficiently alter the results so as to eliminate any 
difference due to the changes in moisture. This will be discussed 
further under the results of Experiment 2. 

Turning to the determinations of potassium, calcium, and phos- 
phorus, as affected by the lowering of the moisture content, it was 



74 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

found that there is no increased solubihty of these elements. This 
would show that the beneficial effect on plant growth must be due 
to a great extent to an alteration of the physical condition of the soil 
and not to a greater amount of plant food being liberated. 

The results from Experiment i show that the lowering of the 
moisture content previous to planting has a beneficial effect on plant 
growth. Of the changes produced in the soil, the physical, chemical, 
and biological factors must be considered, but in the results obtained 
from Experiment i, it would seem that the change in the physical con- 
dition is the principal factor. 

In Experiment 2, the results of drying a soil are studied in connec- 
tion with the biological changes. The effects on the biological factors 
have been measured by the biochemical changes produced. This ex- 
periment differs from Experiment i in that the soil was dried in a dry- 
ing room at a temperature of 30° C. and may be considered as air- 
dried. 

Before discussing the effects of drying on the physiological changes 
produced as measured by the carbon dioxid production, it will be well 
to consider whether the carbon dioxid produced is a correct measure 
of the bacterial activity. The most important objection to this method 
is that the amount obtained in some cases appears to be too high to 
attribute to bacterial action. The chemical changes produced on dry- 
ing may be partly responsible for the increase in carbon dioxid. 
It can not be said that all the organisms in the soil evolve carbon 
dioxid; but if the most important soil organisms produce carbon 
dioxid and if the changes produced by drying act similarly on these 
organisms, the measuring of the carbon dioxid production should 
give a relative measurement of the bacterial activity. 

The results of the experiment show that a previously dried soil 
gives a greater bacterial activity as measured by the carbon dioxid 
production and nitrification in the soil. There are a number of pos- 
sible reasons to be considered in a discussion of the effect of drying on 
the physiological condition of the soil. 

It has been shown by many investigators that the organisms in the 
soil, except the nitrifiers, are resistant to drying. I.f the nitrifying 
organisms are destroyed on drying the soil, then the increased nitrifi- 
cation must be accounted for through chemical changes produced in 
the soil. The drying of the soil alters the colloidal material and allows 
a greater amount of oxygen to enter the soil. After the soil has been 
wet again an increase is found in the nitrates, which would be due to 
the induced oxidation. 

If in drying a soil a greater amount of plant food is made available, 



Kf.iaN: s'i'ri)ii:s i .\ i iii': dkvinm; oi- soii.s. 



75 



llic bacteria would \)v able to obtain a f^rcatci- siipi)!)- of food. Ac- 
cording to C ireig-Snntb. ibc (Ir) ing of tbc soil wonld destroy the 
waxy substance surrounding the soil i)article and allow the more re- 
sistant bacteria a gi"eater food su|)j)ly. 

The resistance of the organisms to (lr\ing may be due to the 
formation of spores. As it is known that the nitrifying Ijacteria do 
not produce spores, we may consider that the decrease in the nitrify- 
ing organisms ami the increase of the other organisms on drying may 
be due to the abihty of the latter to form spores. In a discussion 
of the causes of the beneficial efi'ect due to drying it is necessary to 
consider the hypothesis of Russell and Hutchinson. Considering that 
the drying of the soil is a partial sterilization, they believe that the 
drying of soils destroys or inhibits the action of the phagocytic or- 
ganisms, and an increase in the ammonifying bacteria results, which 
is beneficial to the productiveness of the soil. 

In an air-dried soil the hygroscopic water may be sufficient to satisfy 
the requirements of the bacteria. The hygroscopic water is held 
around the soil particle as a thin film. This film exerts a very great 
pressure, wdiich, it seems, would not allow the organisms to obtain the 
water or the food enveloped in it ; but if the bacteria themselves w^ere 
included within this film, then sufficient food might be obtained. 

From the results obtained in this investigation and by other workers 
it would seem that the increase in bacterial activity on drying a soil is 
not a question of bacterial numbers, but depends upon the relative 
resistance of the important soil organisms. 

In a consideration of the efifect of drying a soil on the physiological 
condition of the soil, no definite conclusions can be drawn until more 
knowdedge is obtained relating to the effect on the different groups of 
organisms. The subject is very complex and must include many 
factors both chemical and physical, as, for example, an alteration of 
the colloidal material wdiich w^ould allow a greater oxidation. 

The results of these studies show^ that the drying of soil affects the 
physical, chemical, and biological factors, resulting in an increased 
plant growth. The increased crop grow^th on a soil that has been 
previously dried is of importance to the practical question of soil 
management, more especially in the arid regions where the soil is often 
air-dried. 

Bibliography. 

Cameron, F. K., and Gallagher, F. E. 

190S. Moisture Content and Physical Condition of Soils. U. S. Dept. of 
Agr., Bur. of Soils Bui. 50: 7-70. 



76 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Fippin, E. O. 

1910. Some Causes of Soil Granulation. Proc. Amer. Soc. of Agron., 2: 

106-121. 
Fischer, Hugo. 

1912. Vom Trocknen des Bodens. Centbl. Bakt. II : 36 : 346-349. 
Greig-Smith. 

1911. The Bacteriotoxins and Agricere of Soils. Centbl. Bakt. II: 30: 

154-156. 

Howard, A., and Howard, G. L. C. 

1907. The Fertilizing Effect of Sunlight. Nature (London), 82: 2103:456. 
Kelley, W. P., and McGeorge, W. 

1913. The Effect of Heat on Hawaiian Soils. Hawaii Agr. Expt. Sta. 

Bui. 30 : 5-38. 

King, F. H. 

1905. Investigations in Soil Management. U. S. Dept. of Agr., Bur. of 
Soils Bui. 26: 13-205. 
Leather, J. W. 

1912. Records of Drainage in India. Mem. of the Dept. of Agr. in 

India, 2: 63-140. 
Lyon, T. L., and Bizzell, J. A. 

1913. Some Relations of Certain Higher Plants to the Formation of Ni- 

trates in the Soils. Cornell Univ. Agr. Expt. Sta. Mem. i: 9-111. 
Pickering, S. U. 

1908. Studies on Germination and Plant Growth. Jour. Agr. Sci. 2 : 

411-434. 

1908. The Action of Heat and Antiseptics on Soils. Jour. Agr. Sci. 3 : 

33-54- 

Rahn, Otto. 

1907. Bakteriologische Untersuchungen iiber das Trocknen des Bodens. 
Centbl. Bakt. II: 20: 38-61. 

Richter, L. 

1896. Uber die Veriinderung whelche der Boden durch der Sterilisieren 
erleidet. Landw. Vers. Stat. 47 : 269-274. 
Ritter, G. W. 

1912. Das Trocknen der Erden. Centbl. Bakt. II: 33: 1 16-143. 
Russell, E. J. 

1910. The Fertilizing Effect of Sunlight. Nature (London), 83: 2105: 6. 
Russell, E. J., and Hutchinson, H. 5. 

1909. The Effect of Partial Sterilization of Soil on the Production of 

Plant Food. Jour. Agr. Sci. 3: 11 1-144. 

1913. Ibid. Jour. Agr. Sci. 5: 152-221. 
Russell, E. J., and Petherbridge, F. R. 

1913. On the Growth of Plants in Partially Sterilized Soils. Jour. Agr. 
Sci. 5 : 248-287. 
Russell, E. J., and Smith, N. 

1905. On the Question whether Nitrites or Nitrates are Produced by Non- 
bacterial Processes in the Soil. Jour. Agr. Sci. i : 444-453. 

Sharp, L. T. 

1913. Some Bacteriological Studies of Old Soils. The Plant World, 16: 
101-115. 



kmcin: srrmKS in i iii'. duninc of soils. 



77 



Warrington, K. 

iS8j. Dc-kMininalion of Nitric Acid in Soils, Jour. Clicm. Soc. Trans., 
351. 

W'ollny, 1-:. 

1897. l^ntorsncIuni«;cn lihcr dcr Volunivcriindcrunj^cn (Kr I'xxlcnartcn. 
lM)rsch. an I" d. (id), .'\gr.-riiys., 20: 2: 14. 



A C K N C) W I . ED( ; M i; N T. 

The writer desires to acknowledge his profound gratitude to Pro- 
fessor T. L. Lyon, under whose inspiration and direction these results 
have been accomplished; also to Professor W. A. Stocking, Jr., for 
valuable assistance in connection with the bacteriological methods 
used. 



78 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



PROBLEMS OF THE WHEAT CROP.^ 

Mark Alfred Carleton, 

Office of Cereal Investigations, U. S. Department of Agriculture, 
Washington, D. C. 

With a production of nearly a billion bushels of wheat in the United 
States in 1914, and a price of $1.60 per bushel at present in Chicago, 
it might well be supposed that the wheat crop in this country has no 
problems. It is the natural course, however, that expansion and de- 
pression shall follow each other in any industry, and it is exactly at the 
height of prosperity when we must be on our guard in preparation for 
the corresponding period of depression certain to follow sooner or 
later. 

Already there are indications that wheat growing will be attempted 
next spring in places and under circumstances very unusual, with reck- 
less disregard of adaptation or facilities for market. One man pro- 
poses to sow spring wheat in Virginia, another wishes to try durum 
wheat in Kansas. Virginia is in no sense a spring wheat State, while 
in Kansas the hard winter wheat probably is too well established to 
justify the sowing of durum wheat in spite of the premium in price 
of the latter, though durum is fairly well adapted in the northwestern 
counties. 

The scarcity of good seed, also, is already being felt. This con- 
dition will become serious before spring seeding time. The tempta- 
tion at prevailing prices to sell, beyond the limit of seed reserve is too 
great. Even to date, it appears that many have not resisted and others 
yet will yield, it is to be feared, before the winter is over. The 
probability of still higher prices for the next crop should be considered. 
The farmer who disposes of his reserve may be killing the goose that 
lays the golden egg. He should look out especially for durum wheat 
sead, where that wheat is adapted, as the pressure for selling it is par- 
ticularly great because of the premium it commands, and there is need 
of a larger production of this wheat next year. 

1 During the winter months, a lecture is delivered weekly by some official of 
the Bureau of Plant Industry, U. S. Department of Agriculture; before the 
scientific staff of the Bureau. The present paper, one of these " Bureau Lec- 
tures," was presented by Mr. Carleton on February 13, 1915. 



("ARF-i'; i'( ).\ : )I:i.i:ms oi' i iii' \\ iii;\i ( unv. yg 

'I'wo ( i.Assi'.s oi' )I'.i.i:m s. 

The prol)lcnis of \hv w lu'at industry arc of Iwo classes, a^^riciillural 
problems liaviiii; to do with prodiirtion and roniniercial i)r()hlenis 
concerned witli marketing", i^n'adinj^. transportation, etc. 

Only the most important of these problems nnder each class will be 
discussed. r>efore doini^ so. attention should be called to the fact that 
certain pro])lems of niucli moment }ears ai^o are now wholly or almost 
entirely solved. 

Problems Already Sok'ed. — (i) The very serious fungous enemy, 
the bunt of wheat, which once gave so much concern is no^w so easily 
prevented and the means of doing it so well known and thoroughly 
practiced that, except in certain areas, it is no longer a problem. 

(2) In the past our wheat production was seriously limited by the 
insufficiency of spring wheat yields, but over a large part of the w^heat 
area the existing winter varieties would not survive the winters. Now, 
by virtue of the introduction of hardier varieties there is only one 
wheat district (the northern Great Plains), a small portion of another 
district (the Northeastern States) and a few places of high altitude 
where winter wheat is not constantly successful. 

(3) The establishment of winter wheat has not only directly in- 
creased the yield, but has gone far toward eliminating the problem of 
the chinch bug in the North Central and middle Great Plains States. 
T\venty to thirty years ago this insect was a constant parasite of 
spring wdieat but rarely attacked the winter wheat in time to do any 
damage. Now since the production of winter wheat has become 
more general, especially of the earlier winter varieties, many of the 
present generation of farmers hardly know the insect. By the same 
means, the damage from rust has been greatly lessened. 

Problems in the Eastern States. 

Problems of production may best be discussed by geographic dis- 
tricts. First will be cited those of the Eastern States, or the area east 
of about the ninety-sixth meridian. 

Earliness. — There is no locality in wdiich earliness is not a desidera- 
tum in wheat cropping. In the East it is important as a means of 
escaping rust, and in some localities for escaping short periods of 
drought occurring frequently about heading time. 

Lodging. — Lodging is a frequent defect in wheat in this district on 
low lands or in unusually wet localities or seasons. Varieties with 
strong straw are' therefore needed. Accurate breaking tests have 
slwvn much variation in the strength of straw in different varieties. 
Turkey wheat, though resistant to rust and drought, has a weak straw. 



80 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Rust. — The rust problem, a very old one, is still with us, though as 
above stated, the damage from rust the country over has decreased 
considerably in recent years. It would no doubt be an improvement to 
substitute for Poole, Fultz, Currell Prolific, and other soft-kerneled 
wheats, a more rust-resistant variety with other qualities equally good. 

Hessian Fly. — In Maryland, Pennsylvania, and adjacent areas, the 
Hessian fly is sometimes a very serious pest. The only means of 
avoiding its ravages now known is to sow late enough so that the 
fall swarm of flies will have come and gone without being able to de- 
posit their eggs on the young wheat plants. Much investigation is yet 
needed of the relations of the Hessian fly to its host. It is not gener- 
ally known that durum wheats and emmers are very resistant or prac- 
tically immune to this insect, as determined by Professor F. M. Webs- 
ter and his assistants. This fact in itself is of no^ economic advantage, 
as these wheats are not grown much within the range of this insect, 
but hybrids of these wheats with those of the common group which 
would resist the fly and yet possess other qualities required in the 
Eastern States, are quite possible. There is considerable conflict of 
conditions in respect to the resistance of common varieties. For ex- 
ample, Dawson Golden Chaff in Ontario, where it originated, is much 
affected, but in New York is said to be little damaged compared with 
other varieties. 

Winter Resistance. — Winter hardiness is still a problem of some 
consequence in the extreme north for resisting the winter cold, and 
in the South for overcoming the effects of late spring frosts. 

States of the Great Plains. 

Drought. — Almost everywhere west of the 96th meridian, except 
under irrigation, the chief contention is against drought. 

Drought is combated in two ways : ( i ) By the use of resistant or 
early varieties and (2) by proper methods of farming. Drought 
effects are avoided to a considerable degree through earliness in 
ripening. Here again the adoption of winter varieties has been of 
great advantage. Grass wheat and other spring varieties generally 
grown thirty years ago nO' doubt were at least as drought resistant as 
the winter wheats, but were beaten by the latter simply on the score 
of earliness. Varietal resistance, however, is probably the greatest 
factor in overcoming drought. 

In the northern Plains, group adaptation in this respect has been 
solved, at least for a long time. The durum group has shown the high- 
est efficiency. It only remains to adopt the best variety, which at 



CARLF/rON : I'ROItrj'.MS OI' 'l ll|- w ill \T ciu,]- 



8i 



present appears to he Kuhaiika. No (IouIjI druii^liL re.Mbtancc can yet 
be greatly increased by selection within the variety. Pure h*nes have 
already been estal)lished at a few points. There are possibly yet other 
varieties that are l)etter. Vast snbgron})s of dnrunis in India and 
western Asia ai"e \et to bo drawn nj)on. Miidi further investiga- 
tion is needed. 

In the middle and southern Plains varietal resistance is more com- 
plicated, as there is a combination of both cold and drought to over- 
come. Nothing tests the hardiness of a wheat to so great a degree as 
the strong winds of a very dry and very cold winter. For such con- 
ditions the Kharkov variety seems best adapted. Of this variety, in- 
troduced by the U. S. Department of Agriculture from eastern Khar- 
kov, Russia, in 1900, there was a crop of 80 million bushels in Kansas 
alone in 1914. In Montana, which has practically been made a wheat 
State by the use of Kharkov, this variety yields constantly 7 or 8 
bushels per acre more than any other. The better known Turkey 
strain apparently gives better results in a few places. The problem 
of winter hardiness, therefore, for some time a most serious one, is 
now well on the way toward complete solution. However, if winter 
wheat is to succeed in Minnesota and the Dakotas, much improvement 
is yet necessary. 

Tillage. — In the matter of tillage in the Great Plains there is a real 
and serious problem always v^ith us. On this subject is founded orig- 
inally nearly all that is known and much more that is not known in the 
entire literature of so-called " dry farmmg." Accepted views are so 
soon refuted that one must have quite up-to-date information to justify 
him in risking a statement. Nevertheless, all dry-farming experiments 
to date, including especially the extensive Dry-Land Agriculture series 
of this Bureau, show that, as a rule, successful wheat growing in the 
Great Plains must follow at least o-ne season out of three of good 
tillage of some kind. The tillage is best given in the form of an in- 
tertilled crop, where such a crop is possible. There is still, however, 
abundant opportunity for further investigation. It is noted in the 
experiments just referred to that there is greater response in wheat 
following summer tillage or an intertilled crop in the winter-wheat 
area than in the spring-wheat area. 

Leaving Wheat Alone. — In the extreme southwestern Plains, exclud- 
ing central Texas, not the least difficult problem is to convince the 
farmer that he should eliminate wheat entirely. In this district 
straight stock-raising is the only dependable occupation, and no cash 
crop can be expected. The toll exacted by drought, winds and dis- 
tance from markets is too great for wheat to be profitable, 



82 journal of the american society of agronomy. 

Western Intermountain District. 

Under dry farming, the problem of tillage for combating drought 
in the western intermountain district is equally as important as in the 
Great Plains. The details of methods, however, must be different 
because of the occurrence of rainfall in winter instead of summer and 
the lack of organic matter in the soil. The problem of increasing the 
nitrogen content of the kernel has been a serious one in this district, 
but is now partially solved by the rapid introduction of Turkey wheat 
in dry farming. Further improvement in this line is possible. 

The Alkali Problem. — Under irrigation, the great problem in the 
West, overshadowing all else, is the serious and growing menace of 
alkali. Any kind of investigation having for its object the complete 
amelioration of the soil and the proper handling of irrigation water, 
especially the drainage, is of the greatest importance. 

Use of Leguminous Crops. — Leguminous crops in alternation, 
everywhere more or less important, are particularly so in intermoun- 
tain districts where there is a great lack of soil humus. The beneficial 
effects of a legume on the following wheat crop are always great in 
the Western States. In addition to the direct effects, considerable 
residual effects have been noted in three successive wheat crops fol- 
lowing one alfalfa crop. 

Columbia River Basin District. 

There is need of earliness and winter hardiness in this district, but 
two problems stand out in relief as more important than all others. 
These are (i) the shattering of the kernels and (2) the bunt or 
stinking smut of wheat.- 

Shattering. — In all the Pacific Coast and intermountain districts the 
summer dryness and the use of combined harvester thrashers, which 
delay the harvest, make it inevitable that all ordinary wheats, will 
shatter seriously. For a while club wheats, which are very resistant to 
shattering, were largely employed, but when Turkey wheat was intro- 
duced for winter hardiness and more gluten, then the trouble began. 
Spillman's hybrids were made with this difficulty largely in mind. All 
improvements hereafter in this district must consider the problem of 
shattering. 

Stinking Smut. — I have stated that, with one or two exceptions, 
the common smut of wheat is no longer a problem. In this district 
the wheat smut is the most serious of all problems. For some time the 
farmers had insisted that none of the usual treatments would prevent 
smut. The failures were attributed by the experiment station staff to 



CARI.l'.'I'OX' : )I!I.I''.MS Ol-' 'rill'. WIII.AI' CROI'. 



83 



carelessness or inaccuracy in a|)pl\ ini;- llic treatments, inilil linally, 
in some experiments on a larL;o scale, tlie station men liad similar 
failures. \'ery careful tests were then made, and it was found that 
treated seed sown under the same conditions as seed purposely smutted 
produced plants with more smutted heads than the smutted seed. 
The necessary conclusion is that the soil itself is full of smut, and it is 
from this snuit that infection commonly takes place. The prob- 
lem therefore is now one of soil sanitation, and it is a very difficult one 
to handle. Smut has become so abundant, often infecting 15 percent 
or more of the crop, that the cloud of smut spores arising from the 
machine at thrashing time is more conspicuous than the smoke from 
the engine. The combined smut and dust in the dry season of 1914 
was apparently the cause of numerous violent explosions in Whitman 
County, Washington, and adjacent territory. Over 100 separators 
were destroyed through such explosions in that county inside of a 
month, 16 in the vicinity of Pullman in one day. It happens that sev- 
eral dust explosions in flour mills occurred the same year. Therefore 
the whole subject of the manner of ignition of dust clouds and the 
nature of the explosions is now being investigated by the Bureau of 
Chemistry and the Bureau of Mines, the Of^ce of Cereal Investiga- 
tions of this department and the Washington experiment station coop- 
erating. 

The California-x\rizona District. 

The wheats of the California-Arizona district are of the class found 
in Australia, India and Turkestan. Fortunately they are usually re- 
sistant to shattering, a quality much needed in this area. 

Deficiency in Gluten. — The most serious obstacle in California 
wheat culture is the lack of gluten in the kernel. Largely from this 
cause, the wheat crop has decreased to almost nothing in recent years, 
though at one time that State grew more wheat than any other. For 
many years California millers have imported one half to two thirds of 
all the wheat used in their mills, chiefly from the Great Plains States. 
Certain varieties recently introduced have more gluten, but much 
improvement in this line is needed. 

Lack of Organic Matter in the Soil. — From the yield standpoint, the 
greatest need for California wheat is organic matter in the soil. In 
our experiments in the San Joaquin valley, the wheat yield after green 
rye or vetch turned under was not only far larger than in continuous 
cropping, but was 50 percent larger than after summer tillage. Prob- 
ably no line of investigations would yield more important results in 
California than that of rotations and green manuring. 



84 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Commercial Problems. 

The principal commercial problems are about three in number, ( i ) 
the purity of the product, (2) the grading and (3) the demands of 
millers and bakers. 

A Single Pure Variety. — On putting the question to a friend re- 
cently: What is the first problem of the wheat crop? he said "To 
establish one pure variety in a locality." It is a matter of importance, 
probably as much so for the farmer himself as for the consumer. It 
may be a question for some time what variety to adopt, but when once 
adopted, the locality or State should proceed to gain a reputation for 
just that wheat and that only, until there is sufficient difference found 
in favor of a new variety to justify an absolute change. 

Demands of the Miller and Baker. — On the other hand, we are not 
justified in restraining the producer from growing a better-yielding 
new variety merely because the miller is unacquainted with it, and may 
even have to change his methods or machinery to be able to handle it. 
The opposition of millers is therefore often a great problem. Often 
the miller discovers later that it is to his own advantage that the wheat 
has been introduced. Good examples of this condition are the hard 
winter and durum wheats of recent introduction into the Great Plains. 
The millers are now opposing the Chul wheat in California, though 
there is much evidence that it is a better variety in quality than the 
commonly grown White Australian, and far better in yield. 

Grading. — ^This topic is presented here wholly from the standpoint 
of benefit to the farmer that would result from rigid grading and 
payment for the wheat strictly in accordance with such grading. At 
present at country stations there is practically one grade and poor 
• wheat is discounted through a system of dockage^ Often weight is 
made the basis, and, with the average price at 60 cents per bushel, 
prices will vary about i cent to each pound of loss or gain in bushel 
weight. This is not sufficient, as there are other qualities thari weight 
which affect the value. The farmer, therefore, sees no difference 
whether he brings to the elevator first-class or third-class wheat. It 
would be of the greatest benefit to both the miller and farmer if a No. 
2 grade, for example, were adopted as a standard, and the farmer 
then paid a premium for wheat grading better or a discount for wheat 
under No. 2 in quality. The miller would thus get what he pays for 
and the farmer would have before him a constant incentive to furnish 
better wheat. 



ELLETT AND CAKRIIIR: Kl'FICCT OF CLIPriNC, ON GRASSKS. 85 



THE EFFECT OF FREQUENT CLIPPING ON TOTAL YIELD 
AND COMPOSITION OF GRASSES.' 

W. ]). Elijctt and Lvi\rAN Cakkiicr^ 
Virginia Agricultural Expekimkxt Station, Blackshurg, Va. 

A few attempts have been made to compare the quantity of grass 
produced when it is cut frequently and when it is allowed to mature 
for hay; in other words, to approximate the relative yields of pasture 
and meadow. The results of some experiments at the Virginia Agri- 
cultural Experiment Station are presented here as a contribution to 
the knowledge on the subject. Before discussing the Virginia data 
the writers wish to review some of the work done elsewhere. 

At the Michigan station in 1894, Crozier^ reports that one plat of 
orchard grass containing one-twentieth of an acre was cut seven 
times between April 26 and June 8. Another of the same size was cut 
for hay on June 8. The seven clippings gave 29 pounds of dried 
grass ; the plat cut once produced 100 pounds. The experiment was 
repeated in 1896 with the plats reversed. One cut four times between 
May 4 and May 26 gave 60.9 pounds of dry grass ; the other cut only 
on Alay 26, 112.5 pounds. A plat of timothy one by six rods in size 
clipped eight times between April 30 and June 24 gave 15.76 pounds 
of dry grass, while a similar plat cut on June 24 for hay gave 172^ 
pounds. The percentage of crude protein in the frequently clipped 
timothy was 22.62, while in that cut for hay it was only 7.81. 

These results have often been quoted to prove that pastures are 
not as profitable as meadows. There is one serious fault, however, 
with this experiment from the standpoint of contrasting pasturing 
with hay making. In each instance the clipping stopped the same day 
that the other plat was cut for hay. As a rule grasses and legumes 
that are kept grazed or cut through the spring will continue green and 
will grow on throughout the summer, while the aftermath on grass 
meadows cut for hay is slight. 

In an experiment reported by Joulie^ one plat of mixed grasses and 
clovers one year old cut twice gave a yield of 5.57 tons of dry hay per 
acre. A similar plat cut six times made a total of only 3.59 tons per 

1 Presented by Professor Carrier at the meeting of the Washington (D. C.) 
Section of the American Society of Agronomy, February 17, 1915. 

2 Crozier, A. A., Forage Plants and Wheat. Michigan Exp. Sta. Bui. No. 
141: 130-132. 1897. 

^Joulie, H., Journal of the Royal Agricultural Society, 18: 195. 



86 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

acre, but there were 7.12 pounds more nitrogen in the hay from the 
acre cut six times than from the one cut twice. 

Sir John. Sinclair makes the following statement in his Code of 
Agriculture :* 

" Land that has been used to the scythe will often produce more grass, but 
that will not, it is thought by some, support so much stock nor fatten them near 
so well as an old pasture, though it may have been better manured." 

In 1908, the Virginia station, in cooperation with the Office of 
Forage Crop Investigations, U. S. Department of Agriculture, began 
some grazing experiments on permanent blue grass pastures. As 
a part of the work eight one-fiftieth-acre plats were staked ofif on a 
permanent blue grass sod and clipped at varying intervals with a lawn 
mower fitted with a basket attachment to collect the grass. These 
plats were intended to be used to corroborate the results obtained on 
some larger fields that were grazed with animals. One of these small 
plats was disked, one harrowed, and one was disked and harrowed. 
These treatments did not appear to affect the production either on the 
large fields or these small plats, so they are ignored in the present 
discussion. 

The following table gives a summary of the four years' work : 
In addition to the cultural treatments, an experiment was con- 
ducted in which heavy and light grazing were compared. On some of 
the plats the frequency of clipping was arranged in imitation of this 
heavy and light grazing. One plat was clipped every week, three every 
ten days, two every twenty days, one every thirty days, and one was 
allowed to mature and was cut once each season, usually in July, fot 
hay. After the first season, the dried grass was sampled and a pro- 
tein determination made of each clipping by the chemical department 
of the Virginia station. The original plan was followed for five 
years before the work was changed. This gave data on weights and 
protein content of all the samples of grass for four years. 



Table i. — Total Yield of Air-dry Hay for Four years from 1/50 Acre Plats 
Cut at Various Intervals, with the Percentage o'f Protein and the Total Protein 
Content in Each Lot. . 



Number of 
Plats. 


Frequency of 
Cutting. 


Air-dry 
Substance. 


Average Protein 
Content. 


Total Protein. 






Pounds. 


Percent. 


Pounds. 


I 


Every 7 days 


111.34 


15-58 


17-36 


3 


10 


112.93 


14.84 


16.76 


2 


20 " 


114-93 


14-43 


16.58 


I 


" 30 " 


138.45 


12.67 


17-93 


I 


Once a year 


197-25 


8.25 


16.28 



* Sinclair, Sir John, Code of Agriculture, First American Edition, p. 281. 
1818. 



KLLKTT AND CAUKIKK: KI-Fl-XT OF CI.IPIMNC. ON CRASSKS. 8/ 

In the spring of i()i3 the plan of llic experiment was changed to a 
test of fertihzers. 'J1ie plat thai was cli])pe(l every seven days and 
the one that w as cnt once a \ ear were left mi fertilized, hut the frc- 
qnency of cutlinf^ of these two plats was reversed. The one which 
previously had been cut once each year was cut every week, and the 
one that had been frequently clipped was allowed to mature for hay. 
There were also three unfertilized plats in the series which were cut 
every fourteen days. The results from these five plats for the year 
are given in Table 2. 



Table 2. — Yield of Air-dry Grass in 19 13 from 1/30 Acre Plats Clipped at 
Various Intervals, with the Percentage of Protein and the Total Protein Con- 
tent in Each Lot. 



Number of 
Plats 


Frequency of 
Cutting. 


Air-dry 
Substance. 


Average Protein 
Content. 


Total Protein. 






Pounds. 


Percent. 


Pounds. 


I 


Every 7 days 


18.13 


15.22 


2.76 


3 


" 14 " 


17-75 


14-31 


2.54 


I 


Once a year 


30.5 


7.00 


2.14 



From these experiments it seems safe to draw the following con- 
clusions for permanent blue grass sod : 

1. The total yield of dry matter varies inversely with the number 
of times it is cut during the growing season. 

2. The percentage of protein in grass decreases as the grass matures. 

3. The decrease in percentage of protein when the grass is allowed 
to mature is sufficient to more than counterbalance the increase in 
weight of dry matter. 

4. The increase in weight of mature grass over frequent clippings 
must be fiber and other nitrogen-free substance. 

5. The cost of hay making would probably offset the gain in carbo- 
hydrates in the case of blue grass so that land utilized as a permanent 
pasture should be more profitable than it would be as a permanent 
meadow. 

It may be of interest to state that the botanical character of the 
herbage varied greatly with the frequency of the cutting. On the 
plats that were frequently clipped blue grass, redtop and white clover 
predominated, while on those that were cut less frequently, especially 
on the one that was cut but once a year, these tame grasses gave way 
to rank-growing weeds such as wild carrot, paspalums, yarrow, white 
top, etc. This undoubtedly had much to do with the amounts of 
protein produced. 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



AGRONOMIC AFFAIRS. 
MEETINGS OF THE SOCIETY. 

The annual meeting of the American Society of Agronomy, as 
previously announced, will be held August 9 and 10, 191 5, at Berkeley, 
Cal., on the campus of the University of California. On. the same 
days, the Society for the Promotion of Agricultural Science and the 
American Farm-Management Association will hold their annual meet- 
ings. Two joint sessions of the three organizations just named are 
planned, as well as two or more separate sessions. On the three days 
following (August 11-13), the Association of Agricultural Colleges 
and Experiment Stations will meet at Berkeley, while the meeting of 
the Association for the Advancement of Science and its affiliated so- 
cieties will occur the week previous (August 2-7) in San Francisco. 
These meetings and the Panama-Pacific International Exposition 
should attract a large numer of agronomic workers to the City of the 
Golden Gate during the first two weeks in August. 

Several members of the American Farm-Management Association 
are planning to meet in Chicago, St. Paul or Omaha and make the 
trip tO' the Berkeley meeting together, stopping at points of agricul- 
tural interest along the way. Members of the American Society of 
Agronomy who desire to join a party of this nature will be welcomed. 
Those who are interested should write the secretary of the American 
Farm-Management Association, Mr. G. A. Billings, Office of Farm 
Management, U. S. Dept. of Agr., Washington, D. C, stating their 
preference as to routes. 

On July 14-16, a sectional meeting of the society will be held at 
Mandan, N. Dak., in connection with the annual meeting of the Great 
Plains Cooperative Association. The latter organization is composed 
of those engaged in experimental work in the Great Plains region, 
either under State or Federal auspices. It is hoped that a full quota 
of agronomic workers in the Great Plains States and from the Prairie 
Provinces of Canada will be in attendance. Papers for presenta- 
tion at this meeting should be limited to topics of interest in the Great 
Plains. 



AC.RONOMTC Al-FAIKS. 



A call for the lilies of papers for presentation at these meetings was 
sent to all nienihers in I'ehrnary. As yet, very few titles have been 
forwarded to the secretary. Members with suitable material for 
papers are urged to send in the titles at an early date, so that the 
programs, particularly of the annual meeting at San Francisco, may 
be printed early enough for distribution to the members of the society 
by mail. 

BRIEF ARTICLES FOR PUBLICATION. 

The editorial board believes that the members of the American So- 
ciety of Agronomy should make more frequent use of the Journal 
for the publication of brief articles. Incidental phases of an investi- 
gation which frequently have little bearing on the matter in hand are 
often of much interest and importance to other workers, yet they es- 
cape publicity because there seems to be no place for them in official 
channels of publicatio'n. Likewise, notes on lines of work which the 
investigator is obliged to abandon for one reason or another before 
the completion of the experiment often lie buried in official files be- 
cause of their incompleteness, yet their suggestive value to others maj 
be great. It is in the presentation of material of this kind, in the 
publication of brief descriptions of methods, and along similar lines 
that the Journal should render greater service. Articles of this 
nature should be brief, clear and concise, ranging in length from a 
single paragraph to about five typewritten pages. Let us have more 
brief papers ! 

ANNUAL DUES OF MEMBERS. 

Notice of annual dues has been sent to all members by the treasurer. 
To save expense to the society and to prevent the treasurer's duties 
from becoming a burden, members are urged to remit promptly. Those 
who are still in arrears for 1914 lapse automatically on April i. The 
names of lapsed members will be published in the May-June number 
of the Journal, unless they apply for reinstatement and remit dues 
before the date of its publication. 

MEMBERSHIP CHANGES. 

The membership of the society as reported in the previous issue of 
the Journal was 422. Since that time, 19 new members have been 
added and 3 members have resigned, making a net membership at this 
date of 438. Some memberships will lapse according to the constitu- 
tion on March 31, but v^ith the natural increase the total should re- 



90 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



main well above 400. The names and addresses of new members, 
names of members resigned, and changes of address which have been 
reported are as follows : 

New Members. 

Billings, G. A., Farm Management, U. S. Dept. Agr., Washington, D. C. 

Brown, E. B., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

BuRDicK, R. T., University of Vermont, Burlington, Vt. 

Ellison, A. D., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Garland, John J., Agronomy Building, Univ. of Wis., Madison, Wis. 

Hansen, Dan, Experiment Farm, Huntley, Mont. 

Hendry, Geo. W., College of Agriculture, Berkeley, Gal. 

Hill, H, H., Experiment Station, Blacksburg, Va. 

Jones, S. C., Experiment Station, Purdue Univ., LaFayette, Ind. 

KiNZY, Grover, Agricultural College, College Park, Md. 

McCall, M. C, Lind, Wash. 

Merkle, Fred G., Route 3, Box 8, Agricultural College, Amherst, Mass. 
Moomaw, Leroy, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
•Neff, C. E., 1312 Bass Ave., Columbia, Mo. 
Richardson, A. M., Waterville, Wash. 

Thompson, James, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Walster, H. L., College of Agriculture, Madison, Wis. 
Watson, E. B., 17 Budd Hall, Univ. of Cal., Berkeley, Gal. 
Young, M. H., Agricultural College, College Station, Texas. 



Members Resigned. 

Clinton, L. A. Potter, H. B. 

Lloyd, W. A. 



Addresses Changed. 

Brown, C. B., Garden City Substation, Garden City, Kans. 

Engle, C. C, College of Agriculture, New Brunswick, N. J. ■ 

Gaines, E. F., Bussey Institution, Forest Hills, Mass. 

Gieseker, L. F., Experiment Station, Bozeman, Mont. 

Grantham, Geo. M., Experiment Station, East Lansing, Mich. 

Hanger, W. E., 133 West Ninth Ave., Columbus, Ohio. 

Hendrick, H. B., Office Exp. Stations, U. S. Dept. Agr., Washington, D. C. 

KiNNAiRD, R. A., Normal School, Maryville, Mo. 

Klein, Millard A., Barnard Apt. 3, Omaha, Nebr. 

LiLL, J. G., Arkansas Valley Substation, Rocky Ford, Colo. 

LoDS, E. A., Demonstrator, Cowansville, Quebec, Canada. 

TiNSLEY, J. D., 507 Union Station, Galveston, Texas. 

Tucker, Geo. M., Office Exp. Stations, U. S. Dept. Agr., Washington, D. C. 
Umberger, H. J. C, Extension Division, Agr. College, Manhattan, Kans. 
Whiting, Albert L., 504 East Chalmers St., Champaign, 111. 
WooDWORTH, C. M., Agricultural Hall, Univ. of Wis., Madison, Wis. 
ZooK, L. L., North Platte Substation, North Platte, Nebr. 



ACRONOM IC A KK A 1 US. 



91 



NEW BOOKS. 

Tlic i 'liciiiislry of . lyriciiltitrc for Sliidcnts ami I'armcrs. \\y 
e'li AULi'S W. Stoddart, l^rr.l)., Professor of Aj^riniliiiral Chemistry, 
Pennsylvania State Collei^e. Lea & l^'e'bif^er ( Philadelphia and New 
York), 191 5. 8 vo. Paiges 347 -\- vi ; figs. 83 ; plates i. 
It seems to be almost inevilal)le that writers and teachers of the 
fundamental sciences as applied to agriculture and home economics 
go to the one extreme of presenting the subject in the pedagogical 
form of the science itself, with an undesirable minimum of illustrations 
from the field of daily life, or to the other extreme of presenting a 
series of unrelated facts concerning the scientific properties of the 
substances dealt with in major courses of instruction in these voca- 
tional branches. To those who hold that instruction in agricultural 
chemistry should consist in the presentation of a series of facts con- 
cerning the chemical constitution and properties of the compounds 
concerned in plant and animal growth and of the physiological changes 
which they undergo, with no serious attempt at an understanding of 
their relationships or the principles underlying these changes, Dr. 
Stoddart's new book will prove thoroughly satisfactory. 

The author states that the book is written to meet the need " for a 
text on general agricultural chemistry which will cover the field 
briefly, in a logical manner, giving only the facts, and not consisting 
of a disconnected series of quotations and tables from the very ex- 
tended literature of the subject." 

The arrangement which seems to the author to be " logical " pre- 
sents in Part I a discussion of the plant, starting w^ith the germina- 
tion of the seed and the growth of the plant, followed by a discussion 
of the composition of plant compo'unds and of farm crops; in Part II, 
the factors in plant growth, including the air, the soil, fertilizers, insec- 
ticides and fungicides, and the gas engine ; and in Part III, the chemis- 
try of animal life, including animal physiology, food and digestion, 
and milk and dairy products. This arrangement involves certain diffi- 
culties, such as the necessary discussion of changes in compounds dur- 
ing germination and growth before the nature of the compounds them- 
selves has been explained, the inclusion of insecticides and fungicides 
and the gas engine as factors in plant growth, a rather inadequate 
presentation of the relation of the composition of plants to their use by 
animals as food, etc. 

The belief of the author that the book is sufficiently elementary to 
make it of value to any intelligent reader " even though he be without 
previous training in botany, chemistry, geology and physics, seems 



92 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

hardly justified from the standpoint of chemistry at least, by the 
inclusion of a large number of complex graphic formulas with no 
explanation of their meaning and of frequent allusions to acid, alde- 
hyde and ketone groups, esters, etc., with no explanation of the mean- 
ing of these terms or of their relationships. 

The text is commendably free from inaccuracies of statement, but it 
is to be regretted that a few such glaring ones should have appeared 
as the properties (of oils) are the same whether the oils are so-called 
mineral oils, ... or are vegetable oils, ... or are volatile oils also 
found in plants" (page 72) and "proteins occur in the granular or 
crystalline form" (page 38). 

The illustrations, while many of them are of common farm scenes 
and hence do not illustrate particular principles of agricultural chem- 
istry, are excellent, being unusually sharp, clear and well-reproduced, 
and add much to the attractiveness of the book. The book itself is 
well made mechanically and attractively bound. 

While the reviewer does not personally approve of the fundamental 
conception of the method of instruction in agricultural chemistry 
presented in the book, he welcomes its clear and accurate presentation 
of the present opinions of our best agricultural chemists concerning 
the chemical compounds and physiological changes involved in plant 
and animal growth as a distinct addition to the elementary literature 
of this subject.— R. W. T. 

NOTES AND NEWS. 

Dr. Charles E. Bessey, for the past thirty years professor of botany 
at the University of Nebraska and one of the best-known botanists in 
America; died at his home in Lincoln, Nebr., February 25, 191 5, in his 
seventy-first year. The value of a training in economic botany re- 
ceived under Dr. Bessey will be attested by many agronomists. 

E. A. Bryan, for many years president of the Washington State 
College, has resigned, efifective January i, 1916. 

Dr. George N. Coffey, for the past several years in charge of soil 
fertility investigations at the Ohio station, is now assisitant State 
leader in county agent work in Illinois, with headquarters at Urbana. 
It is understood that Dr. Coffey will devote the major portion of his 
time to soil problems. 

E. F. Gaines, cerealist of the Washington station, is on leave of 
absence till July i to pursue graduate study in plant breeding at 
Bussey Institution, Forest Hills, Mass. 



Ar.RONOMU: AlMvAIUS. 



93 



T.. F. (licsckcr, who lias ])vcu piirsninm- graduate studies in soils 
and plant hrcodin^;- at C ornell University since September, igfT,, has 
rctnrned to his former position with the Montana college and station. 

W. K. 1 lankier, fonnerl}- of the Maryland Agricnltnral College, has 
been a member of the teaching force in lield croj) production at ( )hio 
State University since January i. 

II. B. Hendrick, formerly extension assistant in agronomy at the 
Kentucky college, is now assistant in agricultural education in the 
Office of Experiment Stations, U. S. Department of Agriculture. 

T. A. Kiesselbach, agronomist of the Nebraska station, spent the 
month of February in Washington, D. C. During his stay, he de- 
voted most of his time to a study of the literature of the water re- 
quirements of plants, in the library of the U. S. Department of Agri- 
culture. 

L. A. Moorhouse, recently agronomist of the Manitoba college of 
agriculture, is now in charge of a study of sugar-beet production as a 
farm enterprise, in the Office of Farm Alanagement, U. S. Department • 
of Agriculture. 

W. R. Skelly has been appointed an instructor in farm crops and 
botany at Purdue University. 

Dr. Charles W. Stoddart, chemist of the Pennsylvania college and 
station, is the author of a new book entitled " The Chemistry of Agri- 
culture for Students and Farmers," published by Lea and Febiger. 

H. J. C. Umberger, formerly of the office of cereal investigations, 
U. S. Department of Agriculture, and for the past three years engaged 
in farming at Hymer, Kans., on March i became demonstation super- 
visor in the extension division of the Kansas college, with headquarters 
at Manhattan. 

Recent appointments in the office of forage crop investigations, U. S. 
Department of Agriculture, include H. R. Reed, by transfer from the 
Philippine Department of Agriculture, assigned to the field station at 
Bard, Cal., and Leroy Moomaw of the Missouri college of agriculture, 
assigned to the Judith Basin substation. Moccasin, Mont. 

The following changes in field-station assignments have recently 
been made in the office of dry-land agriculture, U. S. Department of 
Agriculture: A. J. Ogaard, from Williston, N. Dak., to Hettinger, 
N. Dak., as superintendent of substation, znce H. C. McKinstry, re- 
signed to engage in ranching in Wyoming ; J. T. Sarvis from Ardmore, 
vS. Dak., to Alandan, N. Dak., as agronomist of the Northern Great 



94 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Plains Field Station; W. M. Osborn from North Platte, Nebr., to a 
new station at Lawton, Okla. ; L. L. Zook, by transfer from the office of 
corn investigations, to North Platte, Nebr. ; C. B. Brown, from Dal- 
hart, Texas, to Garden City, Kans., vice ]. G. Lill, transferred to the 
office of sugar-beet investigations ; and L. N. Jensen, from Woodward, 
Okla., to Amarillo, Texas, vice C. W. Burmeister, transferred to the 
office of markets. 

Cereal Conference in California. 

An interstate conference on investigations of cereals to be held 
in California, has been announced for May 25-28, 191 5. This is a 
conference on investigations in all phases of cereal research, at which 
such topics will be discussed as (i) Problems of Pacific Coast wheat 
production; (2) improvement of barley for the Pacific Coast; (3) 
problems in cereal smuts; (4) grading, milling, malting, and baking; 
(5) weed control in cereal production; (6) tillage and crop rotation; 
and (7) insect enemies of cereals. It is expected that Dr. F. K^lpin 
Ravn, Professor of Plant Pathology at the Royal Agricultural Col- 
lege, Copenhagen, Denmark, will be present. The conference will 
meet at Merced, Cal., Tuesday, May 25, for a field inspection of 
cereals in the San Joaquin Valley ; on May 26 the conference proper 
will begin at the University of CaHfornia, Berkeley ; on May 27 
the program will be continued at the University Farm, Davis, in- 
cluding an inspection of the farm ; and on May 28 the plant intro- 
duction garden at Chico and the cereal field station at Biggs will be 
inspected. Agronomists and others interested in cereal production 
are cordially invited. Those who expect to attend should notify 
Dr. J. W. Gilmore, University of Cahfornia, Berkeley, Cal., or Mr. 
M. A. Carleton, Department of Agriculture, Washington, D. C. 

A New Local Section in Iowa. 

A local section of the American Society of Agronomy was organized 
at Iowa State College, Ames, Iowa, on February 9, 1915, with a total 
membership of 28, 19 of whom are members of the general organiza- 
tion. Meetings will be held on the second Tuesday of each month 
during the college year. The officers for 1915 are as follows: Presi- 
dent, Ross L. Bancroft; Secretary, R. A. Needham ; and Treasurer, 
J. A. Krall. 



A(iU()\().M IC Al'l \IUS. 95 
AFl'I'Tl OK I' III'; WASillNtiTDN, D. C, SkCTION. 

The sevcnlh nicotinic ol tlic Washington section was held at the 
Cosmos Chih, Washington, 1). ("., on Wednes(hiy evening, h'ebruary 
17, 191 5. About 55 members and guests were present. Mr. G. W, 
AForgan discussed certain features of the uniform experiments con- 
ducted by the Office of Dry-Land Agriculture at numerous stations in 
the Great Plains, under the title " Comparison of Spring and P'all 
Plowing in the Great Plains Area." He presented figures and charts 
to show that at nine stations in this area from Akron, Colo., north- 
ward, in experiments conducted from two to six years, the increase in 
moisture content from harvest to seeding time the following spring 
was greater on spring-plowed than on fall-plowed plats, and that the 
yield was also greater from spring plowing. At three stations in 
Kansas and Texas, the results slightly favored fall plowing. In all 
cases, the plats were cropped continuously to spring wheat. 

y\r. Lyman Carrier presented a paper entitled " The Effect of Fre- 
quent Clipping on the Total Yield and Composition of Grasses." This 
paper appears elsewhere in this issue. 

In an illustrated paper on Some Features of Rice Culture," Mr. 
Chas. E. Chambliss discussed interestingly the features in which the 
culture of rice resembles and those in which it differs from the culture 
of the other cereals. He stated that the water applied to rice in the 
Louisiana and Texas area and in California amounted to about 2.35 
and 4.65 acre-feet respectively, but that the total water used by the crop 
was practically the same in both areas, because of the greater rainfall 
on the Gulf Coast. Mr. Chambliss spoke briefly of the experiments 
in rice culture conducted cooperatively by the Louisiana station and 
the U. S. Department of Agriculture at Crowley, La., and of the re- 
cent development in rice culture in California. In the latter State the 
first commercial planting was made in 1912, v^hile in 1914 rice was 
grow^n on 16,000 acres, the resulting crop having a value of $800,000. 

The evening closed with a social hour, with refreshments. 

COMING EVENTS. 

Under this caption it is proposed to keep standing a schedule of 
coming meetings of various organizations more or less closely con- 
nected with agronomy. Secretaries of such bodies are invited to 
furnish information regarding their meetings. 

American Society of Agronomy. 

Special meeting, Mandan, N. Dak., July 14-16, 191 5, in connection 
with the meetings of the Great Plains Cooperative Association. 



g6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Annual meeting, University of California, Berkeley, Cal., August 
9-10, 191 5. (In connection with meeting of Assoc. Agric. Coll. and 
Exp. Stations.) 

American Association for the Advancement of Science. 
San Francisco, Cal., August 2-7, 191 5. 

American Association of Agricultural College Editors. 
Madison, Wis., June, 1915. 

American Genetic Association. 
San Francisco, Cal., August 2-5, 191 5. 

Association of Agricultural Colleges and Experiment 

Stations. 

University of California, Berkeley, Cal., August 11-13, 191 5. 

Great Plains Cooperative Association. 
Mandan, N. Dak., July 14-16, 1915. 

LOCAL SECTIONS. 

Cornell University and Experiment Station. 

President, Millard A. Klein. 
Secretary, 

Iowa State College and Experiment Station. 

President, Ross L. Bancroft. 
Secretary, R. A. Needham. 

Kansas Agricultural College and Experiment Station. 

President, W. M. Jardine. 
Secretary-Treasurer, C. C. Cunninghara. 

Washington, D. C. 

President, H. N. Vinall. 
Secretary-Treasurer, P. V. Cardon. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. 7. May-June 1915. No. 3. 



SULFUR AND PERMANENT SOIL FERTILITY IN lOWA.^ 

P. E. Brown and E. H. Kellogg, 
Iowa Agricultural Experiment Station, Ames, Iowa. 

Introduction. 

Sulfur has long been known to be one of the essential plant food 
constituents. It has always been believed, however, that there was 
sufficient present in all soils for the optimum growth of crops. This 
assumption has been very largely based on Wolff's analyses^ of the 
ashes of various crops, which showed the presence of very small 
amounts of sulfur. 

The recent work of many investigators has demonstrated, however, 
that the amount of sulfur in plant materials as determined in the ash 
is, in most cases, entirely too low. There is a considerable loss of 
sulfur in the process of igniting, and the amount found in the ash, 
therefore, may be a very small part of that originally present in the 
plant tissues. 

Investigations in Wisconsin. 

Hart and Peterson^ ha^-e summarized the work of previous inves- 
tigators and have themselves made analyses of numerous farm 
products for sulfur content, using the Osborne method. A com- 
parison of their results with the earlier analyses of Wolff showed 
definitely that by the old method a large portion of the total sulfur 
in all plants was volatilized in the ignition, in some instances as much 

1 Contribution from the Soil Chemistry and Bacteriology Laboratory, Iowa 
Agricultural Experiment Station. Received for publication February i6, 1915. 

2 Wolff's Aschen Analysen. 

2 Hart, E. B., and Peterson, W. H., Sulfur Requirements of Farm Crops in 
Relation to Soil and Air Supply, Wis. Agr. Expt. Sta. Research Bui. 14, 191 1. 



97 



98 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



as 90 per cent being lost. They also showed that the sulfur content 
of crops or the amount of this element removed from the soil by the 
growth of most farm crops was much greater than had previously 
been supposed. 

It is evident, therefore, that the amount of sulfur present in soils 
may be of considerable moment in soil fertility studies and that some 
soils may be deficient in this element to such an extent that crops 
may suffer. Indeed, the evidence of several experiments tends to 
show that sulfur may be the limiting factor of growth in certain 
cases just as nitrogen, phosphorus and potassium are so often found 
to be. 

Hart and Peterson analyzed several soils for total sulfur. They 
found that normal soils in Wisconsin were relatively poor in this 
constituent, containing from 0.033 to 0.140 percent of sulfur trioxide 
(SOo). Most of them, however, contained less than o.i percent. 
This amount was practically the same as the content of phosphorus 
pentoxide (P2O5) in the soils. They showed also that soils cropped 
for 50 to 60 years and either unmanured or receiving but slight 
applications during that period lost on the average 40 percent of the 
sulfur trioxide originally present, as determined by comparison with 
virgin soils. Where farm manure was applied in regular and fairly 
liberal amounts, however, the sulfur content of the soil was main- 
tained and even increased. After a careful consideration of the 
data secured at Rothamsted on the loss of sulfur in drainage water 
and the addition of that element to the soil in the precipitation they 
conclude that losses of sulfur from the soil by drainage and cropping 
are larger than can be met by the amount brought down in the rain. 
Some carrier of sulfur, such as farm manure, superphosphate, am- 
monium sulfate, sulfate of potassium, or gypsum must be applied to 
soils, therefore, if they are to be maintained in a permanently fertile 
condition. 

Investigations in Kentucky. 
The analyses, of numerous Kentucky soils given in a bulletin by 
Shedd* received after this w^ork was under way confirm the earlier 
work in Wisconsin. Constant cultivation without manuring was 
again shown to lead to a loss of sulfur from the soil and the amounts 
of sulfur present were usually found to be smaller than the amounts 
of phosphorus. As a rule, the better agricultural areas showed a 
higher sulfur as well as a greater phosphorus content, leading to the 
conclusion that there is a close relation between the sulfur and phos- 

4 Shedd, O. M., The Sulfur Content of Some Typical Kentucky Soils, Ky. 
Agr. Expt. Sta. Bui. 174, 1913. 



IIROWN AND KIll-I.OCC : SULKUU AND SOll> I'I:K'I 1 1 . 1 1 S 



99 



phoriis content of soils .ind tlu'ir ;iL^rionltural vahu'. 1 lie conclu- 
sion was reached also thai the addition of sulfur in some form is 
essential if soils are to he kept fertile pc-rmanentl\'. 

This bulletin also contains a fairly complete list of the experiments 
which have heen conducted in other countries with the use of sulfur 
in various forms. 'Phese foreign investij^ations have shown that 
many crops may be benefited by the api)lication of sulfur to the soil, 
whether it is applied in the form of sulfate which is directly avail- 
able as plant food or whether it is added as free sulfur. The appli- 
cation in the latter form is usually made for the purpose of remedy- 
ing certain fungous or other diseases of plants. The beneficial ef- 
fects, however, have been much greater than could be expected from 
phorus content of soils and their agricultural value. The conclu- 
sion has therefore been reached that the use of the sulfur was of 
value because of the actual addition of an essential plant food con- 
stituent. 

So far as the authors are aware, no further studies of sulfur in 
soils except those mentioned have been conducted in this country. 
It is hoped that the work reported here will add to our knowledge of 
the subject and supplement the Wisconsin and Kentucky results to 
such an extent that the question of sulfur fertilization as a necessity 
for permanent agriculture may receive more widespread considera- 
tion and definite principles may be reached which shall be of more 
than local application. 

The Sulfur Content of Iowa Soils. 

Accepting the evidence mentioned above that ordinary farm crops 
remove considerable amounts of sulfur from the soil, the question of 
the supply of sulfur in the soil becomes very important. If soils 
are not rich in this constituent and materials containing it are not 
applied, it is obvious that sooner or later a deficiency must occur 
and crops will suffer for lack of a proper supply of sulfur. Analyses 
of some typical Iowa soils have been made, therefore, in order to 
ascertain the amount of sulfur present and consequently the need for 
some material containing this element for the maintenance of perma- 
nent soil fertility in Iowa. Some of the samples of soil, the plant 
food content of which is reported in a recent publication,^ were ana- 
lyzed for their sulfur content. These samples were used for the 
reason that they had been carefully chosen as representative of the 
large soil areas of the State. Thus there were samples of the Mis- 

^ Brown, P. E., The Fertility in Iowa Soils, Iowa Agr. Expt. Sta. Bui. No. 
150, 1914. 



lOO JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

souri loess, the Mississippi loess, the Southern Iowa loess, the Wis- 
consin drift, and the lowan drift soils. These samples were taken 
at three depths, as follows : o to 6% inches representing the surface 
soil ; 6% to 20 inches representing the subsurface soil ; and 20 to 40 
inches, representing the subsoil. 

Method of Determination. 

The sodium peroxide fusion method proposed by Osborne and 
worked out by Hart and Peterson, with one important modification 
which will be described later, was employed in this work. The 
method was carried out as follows : 

Ten-gram quantities of the soils, air-dried and ground, were 
weighed out in nickel crucibles, moistened with water and about 10 
grams of a weighed 20-gram portion of sodium peroxide added. 
This was then thoroughly mixed with the soil and the crucible placed 
over an alcohol flame and heated gently until the mass was dry. 
The mixture was then stirred until it was quite white. The re- 
mainder of the peroxide was then added and the crucible was 
covered and heated over a strong flame for about an hour. After 
cooling, the fused mass was removed from the crucible with hot water 
and acidified with HCl. About 10 c.c. of HCl was then added and 
the mixture heated on a steam bath until the fused mass was entirely 
broken up and all the chlorine gas was expelled from the solution. 
The mixture was then transferred to a 500 c.c. volumetric flask and 
made up to volume. 

After settling, an aliquot of 300 c.c. was drawn ofif and the iron 
and aluminum present were removed by the addition of ammonium 
hydroxide and filtering. The filtrate was made slightly acid by the 
addition of a few drops of HCl. This removal of iron and aluminum 
was apparently quite essential for the obtaining of satisfactory re- 
sults. ^yhen these materials were not removed, much difficulty was 
experienced in securing the agreement of duplicate determinations 
and the sulfate precipitates were apt to be contaminated with iron 
and aluminum compounds. The previous descriptions of the method 
do not mention the need for the removal of iron and aluminum, but 
this work indicates that little dependence could be placed upon results 
secured in their presence. They should be removed, therefore, be- 
fore the precipitation of the sulfates. The extent of the interference 
of these constituents undoubtedly depends upon the amounts in which 
they occur in the soils tested. 

It was found necessary also that only a slight excess of acid be 
introduced before the addition of the barium chloride, as a large 



HKOVVN AM) KIIIJ.OC.C. : Sl'I-l-TU AM) SOU. I'I'.K'II 



lor 



amount of llC l i)r(.'\(,Mi(c(l lo a consi(lcral)lc cxti'iit llu- ])rcci|)ilalioii 
of the hariiim sulfate. This precipitation was then |)C'rfornic<l as 
usual \)\ the a(l(htion of lo c.o. of a hot lo percent l)aC'l.^ scjhition to 
the hoilinij liltrate ohtained as descrihed ahove, allowini;- this to stand 
for several hours on the hot plate and then for twenty-four hours, 
filterini^, washin<^-, drying, hcatinj^: over the l)last and wei^hin^'-. Ac- 
cordini^- to this method, no difficultiy w^as exj)crienccd in ol)tainin<( 
an aj^rcement of dui)licate determinations and the results were quite 
satisfactory. 

Results ok DirriikMiNATioNS. 
The sulfate content of the soils was detemined hy shaking lOO 
grams of the soils with 200 c.c. of water in the shaking macliine for 



Table i. — The Total Sulfur and Sulfate Content of Various Iowa Soils Ex- 
pressed in Pounds per 2,000,000 Pounds of Surface Soil, per 4,000,000 
Pounds of Subsurface Soil, and per 6,000,000 Pounds of Subsoil. 



Soil 
No. 


County. 


Surface Soil.^ 


Subsurface 


Soil.2 


Subsoil. 3 


Sulfur as 
Sulfate. 


Total 
Sulfur. 


Sulfur as 
Sulfate. 


Total 
Sulfur. 


Sulfur as 
Sulfate. 


Total I' 
Sulfur. 1 








Missouri Loess Soil 


S. 








4 


Stielby 


38 


751 


Trace 




1,090 


Trace 


1.299 


IS 


Monona 


34 


802 


Trace 




1.396 


108 


1,566 


20 


Woodbury 


34 


753 


Trace 




1,268 


Trace 


1,449 


108 


Page 


Trace 


716 


112 




1,204 


96 


1,140 








Mississipp 


i Loess Soils. 








67 


Muscatine 


36 


441 


Trace 




812 


Trace 


1,002 


77 


Des Moines 


60 


803 


184 




1,052 


156 


1,056 


124 


Powestiiek 


60 


847 


176 




1.372 


126 


1,326 


127 


Johnson 


74 


787 


72 




1.058 


Trace 


804 






Southern Iowa Loess Soils. 






83 


Monroe 


82 


760 


96 




1.054 


138 


953 


89 


Appanoose 


70 


574 


156 




1,140 


210 


1,146 


94 


Decatur 


46 


863 


72 




916 


Trace 


831 


102 


Ringgold 


62 


886 


100 




1. 310 


Trace 


1,292 








Wisconsin Drift Soil 


S. 








30 


Clay 


94 


902 


152 




1,546 


Trace 


1,263 


36 


Kossuth 


40 


1,110 


100 




1. 510 


114 


1.392 


A- 


Story 




1,130 












B 


Story 




892 












C 


Story 




750 












D 


Story 




846 


















lowan Drift Soils. 










42 


Cerro Gordo 


112 


1.233 


188 




1,312 


144 


792 


45 


Floyd 


52 


1,094 






1,438 


102 


795 


46 


Bremer 


54 


647 


76 




1,062 


Trace 


747 


57 


Delaware 


56 


599 


100 




1,016 


108 


1,087 



1 Depth of sampling o to 6% inches. 

2 Depth of sampling 6% to 20 inches. 
2 Depth of sampling 20 to 40 inches. 



I02 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

seven hours, filtering and precipitating with barium chloride and 
determining the sulfates by the use of the sulfur photometer. This 
method was devised by the writers after a long series of experiments 
reported elsewhere.*' The total sulfur content and the sulfate con- 
tent of the soils from the various soil areas are given in Table i. 
These results were obtained by calculating the sulfur in pounds pres- 
ent per 2,000,000 pounds of surface soil, per 4,000,000 pounds of 
subsurface soil, and per 6,000,000 pounds of subsoil. 

Variations in Sulfur Content, 

An examination of Table i will show that there was a considerable 
variation in the content of sulfates in different soils of the same 
type. This is to be expected when it is recalled that sulfates are con- 
stantly being produced in the soil from the insoluble compounds and 
that these sulfates are partly taken up by plants and partly leached 
out of the soil. The amount present in the soil at any one time 
depends, therefore, on several factors, among which are the rate of 
production or the efficiency of the sulfofying bacteria in the soil, the 
crops grown and their sulfur content, and the drainage from the 
soil. No conclusions can be drawn, therefore, from the amounts of 
sulfates present in these soils and the results have not been averaged. 

There was some variation also in the total sulfur content of the 
various soils within the same areas. Thus in Table i, under the 
analyses of the Mississippi loess soils. No. 67 contained only 441 
pounds of sulfur per acre in the surface soil, while the other samples 
showed 803, 847 and 787 pounds per acre respectively. Similarly 
among the Southern Iowa loess samples, No. 89 contained 574 pounds 
of sulfur per acre, while the other three samples of Southern Iowa 
loess soils showed a content of 760, 863 and 886 pounds per acre. 

This variation in sulfur content might be expected, for Shedd has 
pointed out that there was much less sulfur in cultivated unmanured 
soils than in virgin soils. It is quite evident that not only would 
soils of different origin vary widely in sulfur content, but also soils 
of the same origin differentiated by different treatments or under 
different weather conditions would contain quite different amounts 
of sulfur. Averages have been struck for the total sulfur content 
of the soils in the five large soil areas in the State. While these 
averages would undoubtedly be altered somewhat by including the 
results of the analyses of a large number of samples, it is felt that 
they show fairly accurately the amount of sulfur in these typical 
soil areas. 

6 Brown, P. E., and Kellogg, E. H., Sulfofication in Soils, Proc. Iowa Acad, 
of Science, 21 : 7. 



IlKOWN AM) Klll.l.OCd : SrM'lTK AND SOIL 1- I'.UTI F-I'I ■^' 



Sl'l.i rU AM) I 'llOSI'IIOKUS CONTKNT, 

These average results ai)i)ear in 'ral)le 2, together with the average 
phosphorus coutent ol)laine(l hy the analyses of a large number of 
t\pical soils, the results of which h;i\c been j)nl)lishe(l. 



Taulk j. — .Iz'criu/r Sulfur ami riiDSphorus Content of Rcprcsoitativc Iowa 
Soils, Expressed i)i Pounds per Aerc in 2,000,000 Pounds of Surfaee Soil, 
4,000,000 Pounds of Subsurface Soil, and 6,000,000 Pounds of Subsoil. 



Soil. 


Sulfui 


Phosphorus. 


Surface. 


Subsurface. 


Subsoil. 


Surface. 


Subsurface. 


Subsoil. 


Missouri Loess 


755 


1.239 


1.363 


1.538 


2,697 


3.892 


Mississippi Loess 


719 


1.073 


1,047 


I.361 


2,204 


3.003 


Southern Iowa Loess.. 


770 


1. 105 


1.055 


1.368 


2,089 


2,972 


Wisconsin Drift 


938 


1,528 


1.327 


1.395 


2,217 


3.253 


lowan Drift 


893 


1,207 


855 


1,289 


2,207 


2,889 



It will be noted in Table 2 that there was not a wide variation in 
the total sulfur present in the surface soils in the various soil areas. 
The Wisconsin drift was the richest in sulfur, the lowan drift next, 
then the southern Iowa loess, then the Missouri loess, while the Mis- 
sissippi loess was the lowest in this element. As a general rule, the 
drift soils appeared to be higher than the loess soils in sulfur, at least 
in the surface 6% inches. In the subsurface the same relations did 
not exist. The ^Mississippi loess was again the lowest in sulfur, but 
the Missouri loess was higher than the southern Iowa loess or the 
lowan drift soil. Again the Wisconsin drift soil showed the largest 
amount of sulfur. 

In the subsoil further variations between the different soils in re- 
gard to their sulfur content occurred. The Missouri loess here 
showed the largest amount, slightly larger even than the Wisconsin 
drift. The Mississippi loess and the Southern Iowa loess were 
lower than these two and about the same in sulfur content. The 
subsoil of the lowan drift contained the smallest amount of sulfur. 
It is apparent, therefore, that at the surface the drift soils contained 
more sulfur than the loess soils. At the lower depths, however, the 
lowan drift decreased rapidly in amount .of sulfur present. The 
Wisconsin drift also decreased, but in that soil area the amount pres- 
ent in the subsoil was still greater than that in the subsoils under 
most of the other areas. 

Comparing these results with the average amounts of phosphorus 
in these large soil areas, it will be seen that there was nearly twice 
as much phosphorus as sulfur in the surface soils of some of the 



I04 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

large soil areas. In other cases, the differences were not so great. 
The phosphorus content in the subsurface soils and subsoils was very 
much greater than the sulfur content. It has been believed that 
phosphorus was the element most apt to be lacking in Iowa soils and 
that systems of permanent agriculture should all center around it. 
These results show that there is much less sulfur than phosphorus 
in the soils, and hence they indicate that all systems of permanent 
agriculture in Iowa which leave the sulfur out of account would be 
incomplete and insufficient. 

Sulfur and Phosphorus in Farm Crops. 
It will be well to consider here the relative amounts of sulfur and 
phosphorus in the common farm crops and to calculate the depletion 
of soils in these constituents by the growth of ordinary crops. These 
figures are given in Table 3. The percentage of sulfur in the crops 
was obtained from the analyses by Hart and Peterson and the number 
of pounds removed from the soil by maximum crops was calculated 
in each case. 



Table 3. — Pounds of Sulfur and of Phosphorus Removed per Acre by Maxi- 
mum Crops. 



Crop. 


Maximum 
Yield. 


Sulfur Content. 


Phosphorus 
Content. 








Pound;:. 


Corn, grain 


100 Bu. 


8.5 


17 


Corn, stover 


3 T. 


7.5 


6 


Total for corn crop '. . . . 




16.0 


23 


Wheat, grain 


50 Bu. 


4-3 


12 


Wheat, straw 


2.5 T. 


5-9 


4 






10.2 


16 


Oats, grain 


100 Bu. 


6.8 


II 


Oats, straw 


2.5 T. 


9-7 


5 


Total for oat crop 




16.5 


16 


Barley, grain 


60 Bu. 


4.0 


10 


Barley, straw 


1.5 T. 


4.4 


2 


Total for barley crop 




8.4 


12 




400 Bu. 


32.6 


17 




8 T. 


45^9 


36 




4 T. 


15.2 


12 




4 T. 


I3-I 


20 



A brief examination of Table 3 shows that there are quite con- 
siderable amounts of sulfur removed by one maximum crop. Thus 
8 tons of alfalfa hay take out 45.9 pounds of sulfur, and 400 bushels 
of potatoes, 32.6 pounds of sulfur. The amounts of sulfur removed 
are in most cases about the same or slightly less than the phosphorus 
taken out. Comparing these results with the results of the analyses 



HKOWN AM) Kl.l.l.OCC : Sl'I-I'lIK AND SOfK I'l'-UTI 1,1'I V IO5 

of the soils, it will be seen that there is enough snlfiir in the Missis- 
sippi loess soil, the poorest in siilfnr, lo ji^row 44 niaxiimini rr()])s of 
corn, 71 maxiniuni crops of wheal, 22 crops of 400 hushels of pota- 
toes, or 15 crops of 8 tons of alfalfa hay. In the other soils enough 
is present for a slightly larger nunil)er of crops. ()f course, if the 
corn stover and small grain straw are not removed from llic soil and 
the grain croj) alone is to he considered, the "life" of the soil is 
much greater, hut it is evident that there is not enough to keep crops 
well supplied indefinitely. Furthermore, the subsurface soils and 
subsoils are not rich in sulfur and there is no opportunity of supply- 
ing this element, therefore, from the deeper soil layers. 

Addition of Sulfur in Rain Water and Loss by Drainage. 

There is, of course, an addition of sulfur to all humid soils in the 
rain water. Hart and Peterson have discussed this point. Although 
their observations in Wisconsin were not complete, they concluded 
that the amount of sulfur added to humid soils in the United States 
in the rain water would be about the same as in England, and they 
accepted Hall's estimate of 6.8 .to 7.2 pounds of sulfur per acre annu- 
ally. They pointed out also the fact that the loss of sulfur in the 
drainage water may more than compensate for the addition in the 
precipitation. Hall's results were again cited, showing a loss of 20 
pounds of sulfur per acre annually from the unmanured plots and 
34 to 88 pounds from the manured plots in the Broadbalk fields at 
Rothamsted. These results were obtained on the assumption of an 
annual drainage of 10 inches of water. 

It is evident upon comparing these figures that there is more than 
three times as much sulfur. lost from the manured plots by drainage 
than is brought down in the rain. 

Realizing the fact, however, that these figures should hardly be 
considered applicable to all climates and to all soils, the authors con- 
cur in the conservative statement of Hart and Peterson that " loss by 
drainage at least equals and probably exceeds the amount brought 
to the soils from the atmosphere in the humid regions of America." 

In the absence of positive data for Iowa conditions, the length of 
" life " of Iowa soils from the sulfur standpoint has been determined 
without regard either to the addition of sulfur in the rain water or 
to the loss of sulfates in the drainage water. 

It must be understood, therefore, that the following discussion 
which deals with the return of sulfur to the soils, is applicable only 
if the loss of sulfur by drainage and the addition in the precipitation 



I06 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

are equal. If the loss by drainage is much greater, then additional 
applications of sulfur-bearing materials above those recommended 
would be required. 

Maintaining the Sulfur Supply. 

It is evident from the foregoing that some means must be em- 
ployed if the sulfur content of the soils is to be indefinitely main- 
tained. The most practical means of returning sulfur to the soil 
would seem to be by the use of manures. Green manures would be 
of no use, as they merely return the sulfur which they remove from 
the soil. Results reported elsewhere have shown that in ordinary 
soils the sulfur in horse manure and cow manure is readily oxidized 
to sulfates. Analyses of these materials have been made, and upon 
calculation it is found that applications of lo tons of horse manure 
and cow manure return to the soil 12.28 and 16.02 pounds of sulfur, 
respectively. This lo-ton application is the quantity of manure gen- 
erally used. 

It is apparent that such a quantity applied once in the rotation 
would not return sufficient sulfur for one maximum crop of corn, 
much less for the two crops of corn, one of oats and one of clover 
which make up the regular four-year rotation. In order to supply 
enough sulfur for these four crops in maximum yields, it would 
require an application of about 40 tons of cow manure or 50 tons of 
horse manure once every four years, or a yearly application of 10 to 
12 tons. For normal yields, which are about three fourths of the 
maximum, 8 to 9 tons of manure applied annually would be required 
to keep up the sulfur content in the soil. 

These figures are based on the assumption that the corn stover and 
oats straw are removed from the land and form a part of the manure, 
and they are applicable, therefore, under systems of live-stock farm- 
ing. If the stover and straw are left on the soil and only the grain 
removed as in grain farming, 20 to 30 tons of manure per acre once 
in the rotation would maintain the sulfur supply in the soil for maxi- 
mum yields. In grain farming, however, no manure is produced. 
If the sulfur is supplied in this way the manure must be purchased, 
which would prove very expensive, if it were possible. 

In general, then, it is apparent that the production of manure on a 
live-stock farm is quite insufficient to keep up the sulfur supply in the 
soil. Unless manure is purchased and large amounts of commercial 
feeds are used, some other sulfur-containing material must be em- 
ployed if the soil is to be kept permanently fertile. In grain farming. 



ItKOWN AM) Kl.l.l.OCC : SUl.l'UK AND SON, I-IIR'I 1 l.l'l ■^' 



107 



either a lar^o amount of niamnc or sonn- sulfur li-rtili/i-i- luust 1)C 
bought and apphcd, or sooner or later crops will sullci- from a lack 
of this clement. 

The purchase of manure is rarel\ possible, and hence in pi'actically 
all cases commercial sulfur-containing materials must be used. '! here 
are several sulfur fertilizers which may be emploNcd. In the first 
]-)lace. if acid phosphate is used to maintain the phosphorus sui)pl}' in 
the soil, the sulfate present in it as CaSO.^ will suffice to keep up the 
sulfur content. The fact that acid phosphate does contain calcium 
sulfate and that a dehcienc}- in sulfur may occur in soils is an addi- 
tional reason to suggest the use of acid phosphate on soils. 

Calcium sulfate or gypsum as such may be applied to soils. In- 
deed, it often has been used and has proved a valuable fertilizer. It 
has been believed that the beneficial effect of this material was due 
to a stimulating action, but its value has probably been due in part 
at least to the need for sulfur in the particular soil studied. 

Kainit is a fertilizer which is often applied to soils to supply po- 
tassium. It contains sulfates and hence the value of the material 
on some soils may be due in part to the sulfur added. Ammonium 
sulfate is frequently used on soils as a nitrogenous fertilizer, but its 
sulfur content makes it of value also as a sulfur fertilizer. It is not 
believed, how^ever, that kainit or ammonium sulfate should be gen- 
erally employed on Iowa soils, as deficiencies in potassium rarely 
occur and a lack of nitrogen may be more cheaply supplied by growl- 
ing a W' ell-inoculated crop of a legume and turning it under as 
green manure. 

In grain farming, therefore, where manure is not produced, the 
sulfur supply in the soil must be maintained by the use of acid phos- 
phate or gypsum, and inasmuch as phosphorus must be applied in 
some form in such cases, it seems probable that acid phosphate w^ould 
be the logical material to employ, as it would maintain both the 
phosphorus and sulfur supply in the soil. 

Conclusions. 

The results of this work lead to the following conclusions, some 
of which are undoubtedly more widely applicable than just to Iowa 
conditions : 

Iowa soils are show^i to contain small amounts of total sulfur, 
much less on the average than the phosphorus content in the case of 
each of the large soil areas. 

Some of the sulfur removed from the soil by crops may be re- 

t 



I08 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

turned by the use of manure. Generally speaking, the amount of 
manure produced on a live-stock farm is, however, quite insufficient 
to keep up the sulfur content of soils. Unless manure is purchased 
or large amounts of commercial feeds are used, commercial sulfur- 
containing fertilizers must ultimately be applied to maintain Iowa 
soils permanently fertile. In grain farming, where there is no pro- 
duction of manure, all the necessary sulfur must eventually be sup- 
plied by the use of sulfur fertilizers, or sooner or later crops will 
suffer for a lack of this element. 

Inasmuch as phosphorus also must be applied to Iowa soils to 
keep them permanently fertile and acid phosphate supplies not only 
phosphorus but also sulfur, it seems probable that this material may 
be a very logical fertilizer to employ. 



imi'i:r: tiii-: i'koioin i'I'. oi" tiik cultivaticd S()K(;iiums 109 



THE PROTOTYPE OF THE CULTIVATED SORGHUMS.^ 

C11AK1.KS V. Pii'icu, 
U. S. Dkpartmknt of Agriculturi:, Washington, 1). C. 

The problem of detcrniining" the wild ancestor of a cultivated plant 
which has become profoundly modified under domestication through 
long periods of time is complex and difficult. Furthermore, there is 
no criterion as to what constitutes adequate proof, other than the 
consensus of botanical opinion. 

In a general way it may be assumed that the range of diversity dis- 
closed by the varieties of a cultivated plant is greatest in those which 
have been cultivated for a very long period of time, or over a very 
wide area of territory, or both. 

Where no historical record of the origin of a cultivated plant is pre-* 
served — as is the ease with all of our really important food plants, 
most of which have probably been cultivated many thousands of 
years — recourse must necessarily be had to other types of evidence. 
First to be considered are the facts of morphology. Where critical 
comparison of a cultivated plant with its nearest wild relatives discloses 
but one of the latter in which there is essential agreement in structural 
characteristics, the logical conclusion is that the one is the ancestral 
form of the other. Conversely, if any really different character 
occurs in the one not present in the other, there must remain serious 
doubt of their genetic identity. 

Second, there must be some coincidence between the area of dis- 
persal of the wild plant and that of its supposedly domesticated de- 
scendants. In all probability every plant domesticated in prehistoric 
times was first cultivated in some part of the region where it grew 
naturally. The subsequent distribution, which might in time extend 
to widely distant regions, must not be incompatible with its supposed 
point of origin. 

Third, and very cogent, is evidence that discloses sexual affinity. If 
the assumed wild ancestor crosses readily with its supposed cultivated 
derivatives, and especially if such crossing be spontaneous, it is strong 
proof of their close genetic relation. Conversely, if such crossing 
does not take place spontaneously, or is difficult to achieve artificially, 
the plants can scarcely be considered conspecific. 

1 Received for publication February 15, 1915. 



no JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



The actual demonstration of the ancestral relations of a wild plant 
to its cultivated derivatives can perhaps be secured only by again breed- 
ing the latter from the former. Such a demonstration has never been 
fully carried out in the case of any cultivated plant, and perhaps is 
impossible of realization. Most of the profound changes that have 
taken place in domesticated plants are in all probability of the nature 
of mutations, and have arisen at intervals during a long period of 
time and under very diverse conditions. If there be any definite rela- 
tions between mutation and environmental conditions, the enormous 
difficulty of duplicating these is apparent. 

It is questionable if any other crop plant shows as great an assort- 
ment of widely differing forms as do the cultivated sorghums. Thirty 
or more of these have been described in the past as distinct species, but 
there is general agreement among modern botanists that the sweet 
sorghums, the broom corns, and the numerous grain-producing plants, 
including durra, kafir, kaoliang, and the jo war of India, are all varieties 
of a single species profoundly modified during domestication. As 
regards the genetic relationship of these cultivated varieties to the 
nearest wild relatives, there is less agreement of opinion. 

The problem seems to have been examined first by De Candolle^ 
He considers that the cultivated sorghums represent two botanical spe- 
cies, Holciis sorghum L. and Holciis saccharatiis L. although he states 
that botanists are not agreed among themselves. His idea of the 
first species is stated to be represented by a figure in Host'' of a 
dense-panicled sorghum resembling Orange sorgo, and of the latter 
by another figure in the same work of a loose-panicled plant, which is 
otherwise very similar. 

De Candolle's summary of the facts then known led him to con- 
clude that both of the supposed species were originally native to 
Africa, but the data concerning wild forms were admittedly vague and 
unsatisfactory. Apparently he did not even consider the possibility 
of Andropogon halcpensis (L.) Brot. being the original wild plant, 
though this species must have been well known to him. 

• The problem was later attacked by Hackel,* whose main conclu- 
sions may be summarized as follows : 

I. Sorghum can not be maintained as a genus distinct from Andro- 
pogon, as held by Persoon, Trinius, Nees, and Bentham and Hooker. 
The characters relied upon by different authors have been, first, the 

2 De Candolle, A., L'Origine des Plantes Cultivees, pp. 305-308, 1883. 

3 Host, N. T., Icones et Descriptiones Graminum Austriacorum, vol. 4, plates 
2 and 4 respectively. 1809. 

4 Hackel, E., Die Kultivirten Sorghum-Formen imd ihre Abstammung. En- 
gler's Botanische Jahrbiicher, Band 7, pp. 1 15-126. 1886. 



imi'Kk: TiiK I'KoioiN I'l-: oi' I'lii-: cui/ri va'ii:i) souciums iii 



paniculate rather tlian s])icate inllorescenre, hut this is the same in sorg- 
hum and such nndouhted species of . I nd rofyof/on as . pinictatus 
Ro\h., . saccliaroidcs Swart/, and ./. iiiicran/Ii us Knnth; second, tlie 
cihate kxhcules. l)nt tliese are smooth in the American species of 
sorghum; third, the coriaceous lemmas, hut such occur in . hidrof^of/on 
sqiicirrosiis L. f., and are lacking in Soryhii in Cdticscciis Mack.; finally, 
the character of disarticulate rachis relied upon hy Trinius does not 
lu^ld in one cultivated variety of sorghum. As a section or suhgenus 
Soiu/Iniin ma\- he maintained as a fairly natural group of 12 wild 
species, 6 in the ( )1(1 World, 5 in the New, and i common to hoth 
hemispheres. 

2. The wild species nearest to the cultivated sorghums is Andro- 
pogon hale pen sis (L.) Brot. (//. anmdinacciis Scop.), with four va- 
rieties; namely, propinquus^ cjfusus, virgatus and aethiopicus. All 
of these drop their spikelets at maturity by the disarticulation of the 
pedicel, but individual plants differ considerably in the readiness with 
which the spikelets are shed. 

3. Cultivated sorghums, with the exception of a single variety, do 
not drop their spikelets at maturity. This is to be looked upon as 
the result of selection, largely unconscious, as only those grains are 
saved by the husbandman which have not fallen. In course of time, 
this would eliminate all but those with persistent spikelets. A similar 
contrast is seen by comparing rye, wheat, oats, millet, or rice each with 
its nearest wild relative ; the seeds shatter in the wild forms, but are 
held firmly in the cultivated plants. 

4. The spikelets of the cultivated sorghums differ from those of 
Andropogon halepensis essentially only in the larger grains, in the 
development of which the glumes have also kept pace. 

5. Andropogon halepensis (L.) Brot. and all the cultivated sorg- 
hums constitute but a single botanical species, for which the name 
Andropogon arundinaceus Scop, is adopted.^ In this may be dis- 
tinguished two subspecies ; namely, spontaneus, to which belong the 
wild varieties gemiinus, propinqiiiis, effusns, virgatus and aethiopicus ; 
and cerealis, under which are included all the numerous cultivated 
varieties. 

"But with this systematic nomenclature I combine a deeper meaning: / 
express thereby the conviction that all cidtivated forms of sorghuni have de- 
scended from varieties of Andropogon arundinaceus spontancus. I say from 
varieties, because it appears to me evident that the same variety is not the 

5 In Hackel's monograph of the genus Andropogon published in 1889 (De 
Candolle Monogr. Phan. 6: pp. 500-520) he uses the name A7idropog on sorghum 
L. for the collective species; subspecies halepensis in place of spontaneus ; and 
subspecies sativus in place of cerealis. 



I 1 2 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



basis for all. What is more, I believe that H. arundinaceus genuinus {A. 
halepensis sensu stricto) was not at all concerned in it, but that it was much 
more the varieties effusiis, virgatus, and aethiopicus, perhaps also propinquus, 
which furnished the starting point. The influence of the variety T^iV^fa^M^ shows 
itself perhaps in the cultivated forms with elongated panicles (var. Usorum, 
caiidatus) ; from the var. aethiopicus, the forms resembling sacchdratus could 
have developed ; from these, through the shortening of the panicle branches, 
those corresponding to vulgaris; through further rounding and enlarging of 
the grains, the var. cernmis, and so on. Nevertheless, at present no more than 
vague guesses can be made as to the parent stem of the cultivated forms; the 
closer investigation of the cultivated and wild forms, especially in Central 
Africa, will certainly shed more light upon it." (Translation.) 

But he also writes, 

" My investigations have led me to a conclusion which diverges so widely 
from all heretofore expressed that I dare not hope to see it accepted without 
question by the majority of botanists." 

Nevertheless, no serious attempt seems to have been made to 
controvert his conclusions. They have been accepted by most agro- 
nomic writers, who in general speak of Andropogon halepensis as the 
wild ancestor of the cultivated sorghums. On the other hand, botan- 
ists have as a rule maintained A. halepensis {genuinus) as distinct 
from A. sorghum. Ascherson and Schweinfurth^ definitely express 
disagreement with Hackel's opinion that A. halepensis and A. sorghum 
represent but one species. 

Koernicke,'^ in a paper published previous to that of Hackel but in 
the same year reached the conclusion that Andropogon halepensis is 
the ancestor of the cultivated sorghums. Apparently he was familiar 
only with true A. halepensis, that is, the plant with rootstocks. 

In the culture of Johnson grass and numerous sorghums in the 
United States, facts have accumulated which render necessary a crit- 
ical review of Hackel's conclusions. 

Johnson grass {Andropogon halepensis) was first grown in the 
United States about 1830, the seed having been brought from Turkey.^ 
It may now be found persisting spontaneously over much of the area 
south of latitude 37°, the southern boundary of Virginia and Ken- 
tucky westward to Arizona and California. In many places it has 
occupied the land so thoroughly as to be a serious menace to the cul- 
tivation of other plants. 

Broom-corn sorghums were grown in Virginia and probably else- 

6 Ascherson and Graebner, Synopsis der Mitteleuropaischen Flora, Band 2, 
Abt. I, p. 45. 1898. 

7 Koernicke and Werner, Handbuch des Getreidebaues, i: 300. 1885. 

8 Ball, C. R., Johnson Grass: Report of Investigations Made During the Sea- 
son of 1901, U. S. Dept. Agr., Bur. Plant Indus. Bui. 11, p. 7- 1902. 



IMI'KR: Till- PROTOTVPK OF TIIK CULTIVATKD SORGHUMS II3 

where in colonial days. The first sweet sorj^hnni, Chinese sorgo, was 
introdnced into the Ignited Slates in 1853 and was followed a few 
years later 1)\ the introdnction of nnmerous Sonth African forms. 
Since that time sorghnms have been generally cnltivated in the United 
States. In recent years their cnltnre has received great impetus dne 
to the fact that they are especially adapted to the semiarid region of 
the Great Plains from Sonth Dakota to Texas. 

One other sorghum needs special mention. Drummond in 1835 col- 
lected a plant growing spontaneously at New Orleans which was 
named Sorghum dnimmondii by Nees, and later Andropogon sor- 
ghum var. dnunmoridii by Hackel. From the description as well as 
authentic specimens preserved at Kew there can be no doubt that this 
represents the plant called ''chicken corn" in Louisiana and Missis- 
sippi. I'^ntil about 1895 it seems to have been abundant in these two 
States, maintaining itself vigorously and often producing large volun- 
teer crops that were cut for hay. This variety is annual and therefore 
could maintain itself only by producing seed. In recent years it has 
become almost extinct, probably due to the work of the sorghum 
midge. This variety is particularly interesting on account of the 
aggressive manner in which it maintained itself. It undoubtedly came 
from Africa as various specimens from the Niger River region agree 
exactly. 

Briefly, it appears that Johnson grass became well established 50 
years or xnore ago in many parts of the Southern States. Iln 
Louisiana and Mississippi it grew spontaneously in many places along 
with the earlier introduced chicken corn. When other sorghums were 
cultivated they must often have grown where Johnson grass occurred. 
Indeed for the past twenty years at least, sorghum fields infested with 
Johnson grass have been common enough wherever Johnson grass 
grows. Yet in all this time no one has recorded any natural hybrid 
between Johnson grass and any sorghum. Such a hybrid with chicken 
corn might easily be overlooked because the inflorescences of the 
two are similar, but a cross with any of the larger broad-leaved sor- 
ghums would certainly have been noticeable. In response to a general 
letter of inquiry in September, 1912, to experiment station agronom- 
ists, every one answered that he had never seen nor heard of such a 
hybrid. 

In the last two years, however, natural hybrids between Johnson 
grass and sorghum have been found. The first were detected on a 
farm near Chillicothe, Texas, in September, 19 12, and further plants 
were collected at the same place in 191 3. Individuals vary widely, 



114 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



but all agree in having rather broad leaves and most of them have 
rootstocks. In some the panicles are rather loose as in Johnson grass, 
in others more dense. 

In 19 lo at Lockhart, Texas, a supposed hybrid of Johnson grass and 
sorghum was found by Mr. A. D. Alebane. Mr. Mebane did not 
plant the seed, however, but upon request generously presented it to 
the Department of Agriculture in 19 13. 

One other instance of natural hybridization has been found at Pilot 
Point, Texas, the parents being Johnson grass and Honey sorgo. 

It is evident therefore that wdiile natural Johnson grass hybrids do 
occur they are very rare, not at all what would be expected if Johnson 
grass were the immediate ancestor of the sorghum. Incidentally it 
may be noted that all these hybrids have been found in Texas, in a 
region of relatively low rainfall. 

One other line of negative evidence is worth considering. If the 
cultivated sorghums were derived from Johnson grass, it would be 
but reasonable to expect an occasional reversion to the production of 
rootstocks by sorghums, but after much search no such form has 
been found. Under favorable conditions sorghum plants will live two 
seasons or perhaps more, but apparently they never show any tendency 
to produce rootstocks. Particularly instructive in this respect is the 
nearly extinct chicken corn, which has been growing practically wild 
for eighty years. If any of its individuals had acquired the rootstock 
habit, they would survive the general extinction of this variety, but 
none such have been found. 

On the other hand Johnson grass shows no tendency to lose its root- 
stock habit. The valuable character of this grass in producing heavy 
yields of hay is largely offset by its ability to persist as a weed due to 
its rootstock habit. On this account a vigorous search was instituted 
to see if any Johnson grass plants might be found without rootstocks, 
but without success. 

From these facts it must be concluded that the rootstock character 
is deep seated and one to be given great weight in classification. 

The recent introduction into the United States of two wild or semi- 
wild annual sorghums, namely, Sudan grass and Tunis grass, has fur- 
nished a series of facts which throws additional hght on the subject; 
indeed, clears up the major difficulties of the whole matter. The 
former of these was secured from Khartum and the latter from Dr. 
Trabut in Algeria, who, however, writes that he obtained the seed 
from Egypt. These two grasses closely resemble Johnson grass, 
but lack the rootstocks. From the start both of these grasses, espe- 
cially the former, have readily and abundantly produced spontaneous 
hybrids with any sorghums near which they were grown. 



iMi'i:i<; TIM'. rKo'i'OTN' ri'-. oi' Till', ci 'i;ri\'.\'ri:i > S( )K( . 1 1 r .\i s 115 



Sudan i^imss IIkm-cIOic ronlrasls slroii.^ly with joliiisDii jj^rass in 
two characters, 0110 nujipholoj^ical (its lack of rex >! stocks ) and the 
other pliysioloi^ical (its ahilit\' to cross rea(h1\' with the sorghums). 
The conclusion is ccrtainl\ cx idcnt that Sudan ,L;rass is far more closely 
related to sorj^hunis than is Johnson j^rass. 

Ilackel's studies and conclusions were l)ased lar<^^el\' on the char- 
acters displayed hy the (lowers and seeds. Ai)parently he had no data 
relative to hyhridization. and in liis ar<i;ument he practically i^^nores the 
rootstock character, llis work was necessarily mainly with herhar- 
ium material, and this often did not show the underi^round characters. 
The classification he adopted is in outline as follows : 

Atidi'opogoii SorghuiH. 

A. Subspecies halcpcusis. 

var. genu ill lis. 
vaf. eff nsus. 
var. propiiiquus. 
var. virgatus. 
var. aethiopiciis. 

B. Subspecies safivus. 

var. dnnnnioiidii. 

(Numerous cultivated varieties.) 

Hackel knew that Johnson grass, variety gcniiinus^ possessed root- 
stocks and that in znrgatus and crthiopicus these organs were absent. 
About the other two there was great doubt. It is now known that 
rootstocks are produced by propinquus and that in effusiis they do not 
occur. 

Recent studies of the herbarium material preserved in Berlin, Kew, 
and in the United States, together with culture studies of all the forms 
obtainable, have led to the conclusion that Andropogon halepensis and 
Andropogon sorghum represent two botanical species, distinguished 
definitely by the presence of rootstocks in the former and their ab- 
sence in the latter. Based on this distinction Andropogon halepensis 
occurs in the countries about the Mediterranean eastward through 
southern Asia to China, the Philippines and many of the other IMalay- 
sian islands. Through this wide area occur seven distinguishable 
subspecies. Andropogon sorghum^ characterized by the absence of 
rootstocks, is apparently confined to Africa, occurring generally south 
of the Sahara Desert and in ^Madagascar and the neighboring islands. 
In this region occur eleven or more wild races or subspecies from 
some of which it appears that the negroes gather the seed in time of 
food scarcity. 



Il6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



In a previous paper*^ the writer has thus classified the known forms : 

Andropogon halepensis (L.) Brot. Southern Europe, northern Africa, Asia 

Minor eastward to northern India. 
Andropogon halepensis anatherus Piper. Same range as preceding. 
Andropogon halepensis leiostachys Hack. Corsica. 
Andropogon halepensis miliformis (Schultes) Piper. India, Ceylon. 
Andropogon halepensis muticus Hack. India. 
Andropogon halepensis siamensis Piper. Siam. 

Andropogon halepensis propinquus (Kunth) Hack. Philippines, Borneo, 
Buru, China. 

There is no reason to believe that any of the above plants have ever 
been cultivated for the grain or that the cultivated sorghums have 
been directly derived from them. Hackel suggested that propinquus 
might be a starting point for some of the cultivated sorghums, but 
from the fact that it possesses rootstocks and has very small florets 
while the few varieties of sorghum cultivated by the Filipinos have 
very large florets, the suggestion seems quite untenable. 

Andropogon sorghum (L.) Brot. was based originally on cultivated 
varieties, particularly the one commonly cultivated in southern Europe 
with yellow grains and smooth glumes and an Arabian durra with 
white grains and villous glumes. Of the cultivated plant there are 
very numerous varieties. Wild forms occurring in Africa represent 
at least eleven races or subspecies, as follows : 

Andropogon sorghum exiguus (Forsk.) Piper. Egypt, Nubia. 
Andropogon sorghum eichengeri Piper. German East Africa. 
Andropogon sorghum sudanensis Piper. Sudan. 

Andropogon sorghum verticilliflorus (Steud.) Piper. Madagascar, Reunion, 

Bourbon, German East Africa, Natal, Rhodesia. 
Andropogon sorghum effusus Hackel. Nigeria, Kamerun, Spanish Guinea, 

Togo, Congo River. Introduced in Brazil and Venezuela. 
Andropogon sorghum vogelianus Piper. Mouth of Niger River. 
Andropogon sorghum abyssinicus Piper. Gallabat. 
Andropogon sorghum cordofanus (Hochst.) Piper. Kordofan. 
Andropogon sorghum hewisoni Piper. Sennaar. 
Andropogon sorghum niloticus Stapf. Sudan. 

Andropogon sorghum drummondii (Nees) Hack. Nigeria, French West 
Africa. Introduced in United States. 

It is quite certain that more wild races or subspecies of Andropogon 
sorghum will be disclosed by further botanical exploration in Africa. 
Until these are better known it is somewhat hazardous to predict which 
of the wild races have given rise to the cultivated sorghums. If we 

9 Piper, Charles V., Andropogon halepensis and Andropogon sorghum, Proc. 
Biological Soc. of Washington, 28: 25-44. IQIS- 



piimcr: TiiK I'KoTOTVi'K ()!• I 1 1 !•: { I ' I . r I V A I i:i ) soKciiiuMS 117 



assume that no wild form would he cultivated uuless it already pos- 
sessed food value when growinj^^ wild, it would apparently he necessary 
to discard from consideration c.viyiius, ahyssinicn.s\ cichcngcri, and 
siidanciisis. All of these except abyssbiicus have nuich narrower leaf 
hlades than any cidtivated sorghums; all except sudancnsis shatter 
very readily ; and in none is the grain as large as in other wild races. 

Ilcivisoni might well he the ancestor of the durras, which it re- 
semhles more closely than does any other wild race known. The 
durras are largely confined to Eg)pt and Sudan whence they have 
spread northeastward into Asia, Init apparently not into South Africa 
until very recently. 

Drummondii is so similar to cultivated varieties that Hackel asso- 
ciated it with them. It might easily be the ancestor of such varieties 
as Orange and kafir. 

. Niloticus possesses in a wild form grains large enough to be used as 
food. It does not, however, suggest to us any cultivated varieties. 

Vogcliamis looks like a promising grass to cultivate for grain. Kirk 
collected specimens below Mazzaro on the Zambesi River on which 
he noted grows in damp places 4-8 feet high. Fruit eaten by the 
people in times of famine." 

Verticilliflorus does not impress one as having good possibilities as 
a grain crop. It is practically the only race in southern Africa, the 
region where some of the best grain sorghums have originated. On a 
specimen collected by Busse at Kwa-Wasiri, German East Africa, he 
has the following interesting note : 

" Diese Pflanze ist im gabi Sud der cultivierte sorghum sehr ahnlich, nur 
durftiger als dass; vielleicht die durch aberwilderung wiedergewonnen Urform 
von Andropogon sorghum?" 

There is yet too much to be learned about the wild sorghums to 
determine with any assurance which are the actual prototypes of the 
cultivated sorghums. It seems perfectly clear, however, that Andro- 
pogon halepensis and its subspecies as above defined are not at all con- 
cerned. It appears equally clear that not all of the wild races of 
Andropogon sorghum can be considered as probable ancestors of the 
cultivated varieties. The ones most likely to belong in this category 
are hewisoni, niloticus, drummondii and possibly effusus and verticilli- 
florus. The last two races as at present understood are very variable 
and perhaps each name stands for several distinct plants. The prob- 
lem of the wild ancestors of the cultivated sorghums is now so nar- 
rowed that it is reasonable to hope that the details may in the near 
future be definitely determined. 



I 



Il8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



A METHOD FOR TESTING THE BREAKING STRENGTH 
OF STRAW/ 

B. C. Helmick. 
Cornell University, Ithaca, N. Y. 

In breeding work with small grains it may be desirable to select, 
among other characters, for strength of straw. To do this, it is 
necessary to have some apparatus with which one can obtain a fairly 
accurate test of relative strength. The method used in the Plant 
Breeding Department at Cornell University has been as follows : 

" The method employed was to cut the pieces of straw to a length of eight 
centimeters, using the part nearest the root. This piece was then placed across 
an augur hole in a board, the hole being 5.5 centimeters in diameter. A tiny 
bucket was then suspended from the middle point of the piece of straw by 
means of a hook made from wire about one millimeter in diameter. Shot was 
then poured into the bucket at an uniform rate until the straw broke. A very 
fine shot, about No. 12, was used. The combined weight of the bucket and the 
shot required in order to break the straw was considered as the breaking 
strength of the straw."^ 

This of course was only an arbitrary standard, but since the same 
part of the culm was used each time, it gave results which expressed 
satisfactorily the relative strength of straw. To obtain good results 
with this apparatus, however, the operator must be able to pour the 
shot at the same rate for all tests, and to stop the instant the straAV 
breaks. The fact that the shot cannot always be poured at the same 
rate introduces certain errors when this method is used. 

In order to obtain an apparatus to obviate such errors, a machine 
was made which works on the same principle but which is automatic in 
its action. The shot falls into the bucket from a funnel at a uni- 
form rate and the flow is automatically stopped when the straw 
breaks. This apparatus is shown in Plate I, Fig. i. 

This machine consists of a stand 14 inches long by 8 inches wide by 
12 inches high with a flat board top. Through this top a hole is cut 
434 inches long by 2 inches wide. One inch from the bottom of the 
stand and parallel to the top is placed a platform hinged at one end. 

1 Paper No. 51, Department of Plant Breeding, Cornell University, Ithaca, 
New York. Received for publication February 10, 191 5. 

2 Leighty, C. E., Variation and Correlation in Oats (Avena satwa). Cornell 
Agr. Exp. Sta. Memoir No. 4, p. 84, 85. 1914. 



IIKLMICK: TIIK HkllAKING STKKNCTII OK STRAW 



19 



At tlic other end, this platl'orni is fastened to the cut-olT hy a wive in 
such a manner that when the hueket of shot (h-oj)s on llu- jjlatfonii it 




Fig. 4. Cross section of apparatus for determining the breaking strength of 

straw. 

automatically shuts off the flow of shot. The hopper is a' 6-inch glass 
funnel with the stem bent at an angle of about 80 degrees. Over this 
is fitted a tin spout, the lower end of which is filed smooth so that the 
hinged cut-oft' will fit closely when drawn down by the platform, to 
which it is attached by a wire. The cut-off is held open and the plat- 
form held up by rubber bands, although springs might be more de- 
sirable. A sectional view of the apparatus is shown in fig. 4. 

The machine operates as follows: The straw is placed in position 
and the bucket suspended on it; the platform is then released by press- 
ing back the spring at c (Fig. 4) and the rubber band R opens the 
cut-off*. The shot drops from hopper A into bucket B and when 



I20 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



the straw breaks the bucket drops to platform P, forcing it down into 
the position of the dotted Hne P' . This pulls the wire w down, drawing 
the cut-off n into the position of the dotted line n' . The platform 
is held down by a spring at c while the shot is being weighed.' 

In order to show that there is a varietal difference in respect tQ 
strength of straw and that this difference can be measured by the 
machine described above, the breaking strengths of lOO culms each 
of Turkey and Red Wave wheats were taken. These breaking 
strengths are shown by the data presented in Table i. 

Table i. — Frequency Distributions for Variation in the Breaking Strength 
Determinations, Expressed in Grams. 

Number of Individuals in the Respective Classes. 



Class Values in Grams. 


Turkey. 


Red Wave. 


C^I50 


13 




150-300 


46 


17 


300-450 


28 


26 


450-600 


8 


24 


600-750 


3 


17 


750-900 


I 


7 


900-1050 


I 


2 


I 050-1 200 




2 


I2OO-I35O 




4 


I35O-I5OO 


Constants for the two varieties : 


I 



Turkey. Red Wave. 

M = 298.5000 + 10.9432 . M = 541.5000 + 18.2055 

(T = 162.2415 + 7-7373 ^ = 269.9115 + 12.8721 

C= 54-3523+ 3-2694 C= 49-8452+ 2.9084 



Both varieties have a wide range of variation, the breaking strength 
of straw in the Turkey wheat varing from 82 to 902 grams, and that 
of the Red Wave varying from 163 to 1,400 grams. Both varieties, 
however, have about the same coefficient of variability, thus showing 
that the variability is about the same for each variety. The Red Wave 
has a mean breaking strength of 541.5000 ± 18.2055, while that of 
the Turkey is only 298.5000 ± 10.9432, which gives a difference in 
mean of 243.0000 ± 21.2415, a dilference which is over eleven times 
its probable error. Although the number of individuals is not large, 
yet the data herein presented show that such differences may be meas- 
ured with a fair degree of accuracy. 



Journal of the American Society of Agronomy. 



Plate i. 




Fig. 2. Apparatus for Determining Weight per Bushel of Grains. 



love: nicTKUMiNiNC. WKic.irr 1'i:k iuishel 



METHODS OF DETERMINING WEIGHT PER BUSHEL.^ 

H. If. r.ovE, 

CORNKLL UnIVKRSITV, IjIIACA, N. Y. 

In a recent bulletin, Barber,- of the Maine station discussed methods 
for determining the weight per bushel of grains. The need for a 
uniform method for such determinations is pointed out in this bul- 
letin, as is shown by the following statement made by the Federal 
Bureau of Standards in answer to an inquiry made by the Maine 
station : 

" So far as the Bureau has any knowledge on the matter, there is very little 
care or uniformity of method used in filling the bucket with grain, although 
without doubt it is a matter to which greater attention should be given, as 
there is a decided difference in the amount of grain that may be contained in 
a measure according to whether it is struck off level as it falls into the bucket 
or is first shaken down. The most common practice of the matter is, probably, 
to merely dip the bucket into the grain to fill and then strike off the grain 
as it lies." 

Four methods of determining weight per bushel were tested at the 
Maine station. The details of these methods are given briefly else- 
where in this paper. The method used in the department of plant 
breeding at Cornell University has given very satisfactory results, 
and as it dififers in some essentials from those used by the Maine 
station, a comparison of the results obtained by the various methods 
seems desirable. 

When investigations with cereals were begun by the department of 
plant breeding, it was deemed important to use a method for deter- 
mining weight per bushel which would give accurate results and one 
in which all tests would be conducted in a uniform manner. It was 
also desired to use a method which would give results representing 
fiairly the weights per bushel. It seemed that some method which 
would make it possible to fill the bucket in the same manner and with 
the same quantity each time would be satisfactory. 

For this purpose Mr. H. W. Teeter of the department of plant 
breeding designed the apparatus shown in Plate I, Fig. 2. This 

1 Paper No. 52, Department of Plant Breeding, Cornell University, Ithaca, 
N. Y. Received for publication February 27, 1915. 

2 Barber, Clarence W., Note on the Accuracy of Bushel- Weight Determi- 
nations, Maine Agr. Exp. Sta. Bui. 226 : 69-75, 1914. 



122 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

apparatus consists of a stand with a funnel sufficiently large to hold 
more than enough oats to fill the 2-quart bucket, and with an open- 
ing 2 inches in diameter which is closed with a slide. The stand 
is so arranged that the distance between the bottom of the funnel 
and the top of the bucket is 6 inches. The stand may be adjusted 
so that when it is necessary to use a smaller tester the distance will 
be the same (6 inches) as when the larger tester is used. 

With this apparatus, each variety tested may be handled in ex- 
actly the same manner, while different persons may determine the 
weights and obtain comparable results. The tests are not subject to 
the variations which may occur when one forces the grain into the 
bucket or dips the bucket into the grain. There is also an added 
advantage in that the results approximate the actual weight per 
bushel, which is not the case if the bucket is shaken or handled in 
any w^ay that tends to pack the grain. 

In order to make some comparisons between the Cornell method 
and those described in the Maine bulletin, a quantity of oats was 
thoroughly mixed and various tests were made, as described in the 
following paragraphs. As a sample was taken from the lot and 
tested it was put into another container, so that a different sample 
was used for each test. The descriptions of the methods used at 
the Maine station are quoted from the bulletin of that station pre- 
viously mentioned, and the methods are numbered the same as in that 
bulletin. The grain tester was of the same kind as that used at the 
Maine station. The results of each test were read off from the per- 
centage scale and were later changed to pounds. All determinations 
were made by Mr. Teeter, who has had considerable experience in 
obtaining such data. 

The Cornell method consists of filling the large funnel with a cer- 
tain quantity of grain each time. The slide closing the funnel is 
then opened and all the grain permitted to fall into the bucket. The 
measure is then struck in the ordinary manner, which is to draw a 
straight edge of some sort in a zigzag manner across the bucket. 
This was always done before the bucket was moved or shaken in the 
least. 

The methods described in the Maine bulletin were as follows : 

Method I. " The grain was poured into the bucket, filling the same round- 
ing full and was not settled in any way." Then the top was leveled as in the 
Cornell method. From the statement in the Maine bulletin it is not clear whether 
the same quantity of oats was used each time or whether care was taken to 
pour always from about the same height. This was done in the tests cited in 
the present paper, with the exception of certain tests which will be referred 
to later. 



LoN i-:: 1)1': i i;u.M I .\ I \( i w i". i ( ; i ri' nrsiii:!. 



Motluxl II. " 'riu' bucket was lillcd rDUiuliiiK full by dippinj^ it dirrctly iuto 
tlu' ^raiu. Tlio .uiaiu was not settled in any wa>'." Then the top was leveled 
as in the ( "oi iiell method. 

Method 111. " The bucket was filled roundin.n full by dippin)^ it into the 
Lorain and then shaken down once." Afti-r shakinj; tlu' top was smoothed off 
as in the Cornell method. 

Method IV. " The grain was poured into the bucket, lilling it rounding full 
and settled by shaking down live times." After this the straight edge was 
used to level the surface as in the Cornell method. 

The tests wcM'c made in the order given above. It was immediately 
ai)i)areiU tliat the coiitiinioiis haiulling was tending to ])reak off tlie 
tips of the hulls, which would affect the results to a consideraljle 
extent. "To (letermine this point definitely, after the lOO samples of 
each of the live lots had been run another set of lOO was made by 
the Cornell method. These are referred to in Table i as Cornell 
Method No. 2. The results for these determinations are given m 
Table i. 



Table i. — The Frequency Distribution of Determinations of the Weight per 
Bushel of Oais by Different Methods, with Variation Constants for Each. 

[First Set] 



Reading in 
Percentages. 


Cornell iMethod, 


Cornell Method, 




Maine Methods. 




No I. 


No. 2. 


I. 


H. 


III. 


.V. 


46.0-46.4 


I 












46.5-46.9 


I 












47.0-47.4 


35 


12 


32 








47-5-47.9 


37 


67 


53 








48.0-48.4 


24 


20 


13 








48.5-48.9 


I 


I 


2 


3 






49.0-49.4 


I 






10 






49.5-49.9 








19 






50.0-50.4 








41 


I 


2 


50.5-50.9 








16 


3 




51.0-51.4 








7 


24 


14 


5I5-5I.9 








2 


37 


38 


52.0-52.4 








2 


22 


40 


52.5-52.9 










II 


4 


53.0-53-4 










I 




53-5-53.9 










I 


I 


54-0-54-4 












I 



Variation Constants. 



Method. 1 Mean. 


Standard Deviation. 


Coefficient of Variability . 


C. U. Method (i) 

C. U. Method (2) 

Maine Method I 

Maine Method II 

Maine Method III 
Maine Method IV 


30.5248i.0188 
30.5920rb.0111 
30.5120i.0141 
32.1472i.0283 
33.1776i.0241 
33-2384±-0223 


o.278oi.oi33 
.1652 i.0079 
.2o84i.oo99 

.4191 i.0200 

.3570i.oi70 
.33ioi.oi58 


0.9107 i. 0434 
.5400i.0258 

.6830i.0326 
1.3037 i.0622 
i.076oi.o5i3 

.9958i.0475 



124 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

It is seen that the means for the Cornell method (i) and Maine 
method (i) are practically the same. The standard deviations, how- 
ever, are considerably different, the difference amounting to .0696 ± 
.0166. How much of this may be due to the fact that the oats had 
been handled once is impossible to determine exactly. There is evi- 
dently less variation when Method I is used in this case. However, 
when one considers the statement under Method I that the same 
quantity of oats was used for each test and that they were always 
poured from nearly the same height it is clear that there is really 
little difference between Method I and the Cornell method. 

The difference between the means of Methods I and 11 amounts 
to 1.6352 zb .0316. The standard deviation of Method H is greater. 
This is in accordance with the results recorded in the Maine publi- 
cation. The coefficient of variability, however, is greater for Method 
n by .6207 1+: .0702, which shows that the relative variability is 
greater when this method is used. 

The mean increases when Method HI is used in comparison with 
Method n, as is shown by the difference, 1.0304 ± .0372. The dif- 
ferences between the standard deviation and coefficient of variability 
of Methods H and HI are .0621 ± .0262 and .2277 ± .0806 respect- 
ively. This indicates that the variability becomes less as the method 
of filling is changed so that the oats are packed to some extent. 

When Method IV is used the mean is about the same as when 
Method III is used. The standard deviation, however, is slightly 
less, as well as the coefficient of variability. This indicates that the 
settling of the grain tends to lessen the variability to some extent. 
That part of this effect may be caused by the fact that the grain 
had been handled so much is shown by the second test run by the 
Cornell method. This shows the mean to be about the same, although 
slightly increased, while the standard deviation and coefficient of 
variability are considerably less than is shown by the Cornell method 
(i). The differences between the standard deviation and coefficient 
of variability are .1128 ± .0155 and .3707 ± .0505 respectively. This 
indicates clearly that the handling of the oats makes it possible to 
obtain a more uniform sample than can be done at first. 

Since this seemed so important, it was decided to obtain a new lot 
of the same variety of oats and make the determinations in such a 
way that all the samples obtained would be more nearly uniform so 
far as the oats were concerned. This was done as follows: Five 
determinations were made by the Cornell method, then 5 with Method I, 
5 with Method II, and so on until 5 samples had been run by each 



i.ovi: : Di'/n-.uM I N 1 Nc. wi'.ici i r ri:u i!iisiii:i. 



125 



method. The operation was tlicn rcjx-'atcd until 100 <k-lcrniinati()ns 
liad l)ccn made cacli nn-tliod. Tlic rcsnlts arc j^ivcn in 'ral)lc 2. 



Table 2. — The V rcqncncy D'lsir'xhulion of JJclrnuinalions of the Wcifiht per 
Bushel of Oats by Different Methods, with Variation Constants for ILaeh. 

[Second Set.] 



Readings in 
Percentages. 




Maine Methods. 


I. 


II. 


III. 


IV. 


46.5-46.9 


2 


4 








47.0-47.4 


44 


49 








47.5-47.9 


43 


36 








48.0-48.4 


10 


II 








48.5-48.9 


I 




I 






49.0-49.4 






4 






49.5-49.9 






18 






50.0-50.4 






48 






50.5-50.9 






15 


I 




51. 0-51. 4 






9 


• 9 




5I-5-5I-9 






5 


15 


I 


52.0-52.4 








29 


9 


52.5-52.9 








17 


15 


53-0-53-4 








17 


16 


53-5-53-9 








II 


8 


54.0-54.4 








I 


18 


54.5-54-9 










18 


55.0-55.4 










10 


55-5-55-9 










5 



Variation Constants. 



Method. 


Mean. 


Standard Deviation. 


Coefficient of Variability. 


C. U. Method 


30.4448 ±.0144 
30.4i28rt.Oi47 
32.2304rt.0245 

33- 6064 rt. 0323 

34- 4704±-0453 


0.2140 rt.0I02 
.2182 rt.0104 

.3632=t.oi73 
.4796 rt.0229 
.6711 ±.0320 


0.7029 rt. 0335 
.7l75±-0342 
1. 1269 rt. 0537 
1. 4271 rt.068l 

i.9469±.0928 


Maine Methiod I 


Maine Mettiod II 


Maine Method III 

Maine Method IV 



These results do not agree altogether with those given in Table i. 
The mean shows an increase with those methods in which the oats 
are settled. 

The means, standard deviations, and coefficients of variability for 
the Cornell Method and Method I agree very closely, indicating that 
it makes little difference which method is used. In fact, as has been 
pointed out above, there is really no great difference between the two 
methods as performed in our laboratory. It is difficult always to pour 
from the same height, to use the same quantity of oats, etc., therefore 
it is better to use the apparatus which has been described under the 
Cornell method and which any one may duplicate. It is easier to 
give directions which can be followed with this apparatus than with 



126 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



Method I, or in fact with any method where the individuality of the 
experimenter plays an important part. 

The difference in mean between Method II and Method I is 
1. 8 1 76 ± .0286, which shows beyond doubt that the weight per bushel 
is increased with this method. The standard deviation is greater 
when Alethod II is used by .1450 ± .0202, which, considered with the 
difference in the coefficient of variability, .4094 ± -0637, indicates 
that the variability is slightly greater in Method II. When Method 

III is used the mean is greater than that of Alethod II by 1.3760 ± 
.0405. The standard deviation is only slightly greater, the differ- 
ence being .1164 -t .0287, and the coefficient of variability is likewise 
greater by .3002 ± .0867. The two constants indicate slightly the 
tendency to increased variability, although the differences are not 
significant when the probable error of the difference is considered. 

Method IV^ gives a mean slightly higher than Method III. The 
standard deviation and coefficient of variability also indicate that the 
variability is somewhat greater, although the differences between 
the standard deviation and coefficient of variability are not great. 
When Method IV is compared with Method I and the Cornell method, 
a marked difference is shown in the mean, standard deviation, and 
coefficient of variability. The differences in mean between Method 

IV and Method I and between ^Method IV and the Cornell method 
are 4.0576 ± .0476 and 4.0256 ± .0475 respectively. The differences 
are practically the same, showing again the similarity of IMethod 
I and the Cornell method. The same may be said of the differences 
in the standard deviation and coefficient of variability. The differ- 
ences between the standard deviation in the same order are .4529 zh 
.0336 and .4571 ± .0336, while those between the coefficient of vari- 
ability are 1.2294 ± .0989 and 1.2440 ± .0987. 

This clearly indicates for these data that the mean weight per 
bushel is abnormally high and that the variability is not lessened by 
the methods which tend to settle the oats. 

These results are in exact contradiction to those obtained at the 
Maine station. It is believed, as has been pointed out, that as the 
oats are handled more and more the variability of the weights ob- 
tained becomes less, and thai by the method used at Maine the ten- 
dency would be for the last lot of samples taken to become less vari- 
able. This is clearly shown by the results obtained by the Cornell 

3 In this lot under Method IV the tester was filled again after shaking and 
before striking. This was also done in the next lot but not in the first lot in 
Table i. 



T.ovi-: : i)i"ri:KM I M \(i \\ i:i(;ii'r 



127 



method ( I and 2), i^ixcn in Tahlc 1. Aiiollicr reason lOr llu- (lilTer- 
ciicos l)c(\\cHMi tlic Maiiu' rcsnlls and llic ones obtained at ( oiau'll is 
that dilTorcnl persons eondneted the tests. It is not possihk- I'oi- two 
persons to shake a nieasnre se\'eral times and settle it in exaetly the 
same way. It is elear, then, that one person UKiy settle the oats 
more than another and such resnlts could not 1)C used in com])arison 
with those obtained elsewhere. 

Since it has been shown that there was httle (hfTcrencc between 
Afethod I and the Cornell method as the determinations were made 
in our laboratory, it seemed well to make a new set of determina- 
tions in which Method I as described would 1)e interpreted generally. 
That is, nothing is said in the description of the method as used at 
Maine regarding the manner of pouring, nor is it stated whether the 
same quantity of oats was used each time, whether the pouring was 
done all at once or whether small quantities of oats were obtained 
so that the oats might have a chance to settle. 

Table 3. — The Frequency Distribution of Determinations of the W eight per 
Bushel of Oats by Different Methods, with Variation Constants for Each. 



[Third Set] 






Maine Method. 


Readings in Percentages. 


Cornell Method. 






I. 


IV. 


47.0-47.4 


14 


2 




47-5-47-9 


32 


2 




48.0-48.4 


44 


12 




48.5-48.9 


10 


19 




49.0-49.4 




25 




49.5-49.9 




21 




50.0-50.4 




15 




50.5-50.9 




4 




51.0-51.4 








51. 5-51.9 








52.0-52.4 






I 


52.5-52.9 






I 


53.0-53.4 






16 


53-5-53-9 






22 


54.0-54.4 






21 


54.5-54.9 






28 


55.0-55-4 






10 


55-5-55-9 






I 



Variation Constants. 



Method. 


Mean. 


Frequency Distribution. 


Coefficient 
of Variability. 


C. U. Method 


30.7200 ±.0174 
31.5392 ±.0324 
34.688o±.0288 


0.2573±.OI23 
.4803 ±.0229 
.4277 ±.0204 


o.8376±.0399 
i.5229±.0726 
i.2330±.0588 


Maine Method I 


Maine Method IV 



128 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

Consequently, a third set of determinations was made in which the 
Cornell method was compared with Method I, when the pouring 
was done as any person might do or as has been suggested in the 
preceding paragraph. A lot was also run by Method IV the same as 
in the second set (Table 2). The results of these determinations are 
given in Table 3. It is clear from the frequency distributions that 
there is greater range in Method I than was observed in Table i. 

The mean is greater when the results have been obtained by 
Method I as indicated than when obtained by the Cornell method, the 
difference being .8192 ± .0368. This shows that when each deter- 
mination is not made in exactly the same way there is a tendency 
for the oats to settle, especially when enough is not poured in at 
once to fill the bucket rounding full. 

The standard deviation shows a difiference of .2230 ± .0260 and 
the coefficient of variability shows a difference of .6853 ± .0828. 
These constants indicate also that there is greater variability than 
with the Cornell method. 

Again, Method IV shows a greater mean than either of the other 
methods. Greater variability is also obtained than when the Cornell 
method is used. 

Taken as a whole, these results show the need of a uniform system 
for the determination of the weight per bushel of grain. It is evi- 
dent that it is difficult to follow any method that permits of dififer- 
ences due to the manipulator. The method suggested here may not 
be the best, yet it is possible for any person to duplicate it exactly. 
This renders it possible to make all weight per bushel results com- 
parable. This point is very important, since with the methods now 
in use at different places the weight per bushel may vary several 
pounds, depending entirely upon the manner of making the test. 



Members of the American Society of Agronomy who are interested in appa- 
ratus for the accurate determination of bushel weights will be glad to know 
that the office of grain standardization, U. S. Department of Agriculture, is 
developing an apparatus for commercial use which it is hoped will be ready 
to place on the market in a short time. The device does not diff^er greatly 
from that here described by Doctor Love, though it does vary in some par- 
ticulars. When it is ready for the public, further notice concerning it will be 
published in the Journal. — Editor. 



coFFicv AND TiT'm.i:: POP 'I'l-.s'i-s W i l li I'i'.u rii.izi.iv's 129 



POT TESTS WITH FERTILIZERS COMPARED WITH FIELD 

TRIALS.^ 

(iKORClC N. C'OI'FKN' AND II. TUTTIJC. 

Departmknt of Soils, Ohio Agricultural Eximcri mknt Station, 
WoosTER, Ohio. 

Introduction. 

After the reconnaissance soil survey of Ohio had determined the 
important soil types of the. State, it was purposed to make studies 
upon these different types to find out their peculiar requirements. 
Among- the most important of these studies is the determination of 
the relative need of the different types for the three principal fer- 
tilizing elements. 

While field trials are considered the most reliable method of solv- 
ing this question, they are expensive and musi be systematically 
planned and thoroughly executed over a period of years, long enough 
to give a fair average of climatic conditions, which would mean at 
least ten or twelve years," before the experimenter " can feel that 
he has the solid ground of positive knowledge under his feet."^ A 
quicker and less expensive method is therefore very desirable. Sev- 
eral such methods have been proposed, among which may be men- 
tioned chemical analysis, wire basket tests and pot tests. 

The results with pots seemed to give most promise and it was 
therefore decided to make pot tests with soils as similar as possible 
to those upon which field trials are being conducted, and to compare 
the results with those secured in the field. In this work the idea 
has been to duplicate field conditions and treatments as nearly as 
possible. 

Ohio has several experiment farms located in various parts of the 
State on widely different types of soils. Upon these, fertilizer plot 
work has been conducted for periods ranging from ten to twenty 
years. Soils from the farms at Wooster, Strongsville and Carpenter 
have been studied in pot tests and the results so far secured are re- 
ported here. 

1 Received for publication April 21, 1915. 

2 Thorne, Chas. E., How to Determine the Fertilizer Requirements of Ohio 
Soils, Ohio Agr. Expt. Sta. Cir. 79, p. 3, 1908. 



i 30 journal of the american society of agronomy 

Pots. 

The pots used were 5-gallon glazed clay butter-crocks, about 10% 
inches in diameter and 12 inches deep. A small hole, over which a 
piece of broken crockery was placed before filling, was punched in 
the bottom to provide drainage. It was found necessary to have all 
pots as nearly uniform in depth and diameter as possible. 

Collecting Samples and Potting. 

As it was impossible to obtain soil from the unfertihzed field plots, 
samples were taken from unfertihzed land, located as nearly as pos- 
sible to the field pots with which the pot results were to be com- 
pared. One objection to the use of this soil is that the unfertilized 
strips, except at Strongsville, have not been cultivated for years, 
while the plots have been. This difference in treatment has un- 
doubtedly affected their fertility, especially the nitrogen content. 

The surface soil and the first 6 inches of the subsoil were col- 
lected from several places in the same field and taken to the green- 
house as soon as possible, where each was mixed separately by 
shoveling over on a cement floor. Equal weights (about 10 kg.) of 
both soil and subsoil were used in each pot. In potting, a sufficient 
quantity of the subsoil to cover the bottom to a depth of an inch or so 
was placed in the pot. The balance of the earth and enough water 
to saturate it thoroughly were then poured in simultaneously, the 
same quantity of water being used in each pot. The pots were then 
allowed to settle for several days. The surface soil was then added 
to the pots and settled like the subsoil, with enough water to saturate 
it thoroughly. The pots were then left until the soil was in good 
working condition, usually for two or three weeks, when they were 
cultivated, fertilized, and planted. Although it may not be possible 
to settle the soil absolutely by this method, pots which have been 
cropped in the greenhouse for two years have not settled appreciably 
since first planted and it is believed that the method used gives the 
easiest and nearest approach to field conditions. As duplicate tests 
showed little difference from the use of distilled or tap water, the 
latter is now used. 

Treatment. 

Every treatment was tested in tripHcate, applying each fertihzer 
at the same rate as in the field. Commercial fertilizers were used 
in all cases. However, when lime was required, c.p. calcium car- 
bonate was applied some time before fertilizing, by sprinkling the 
desired quantity through a small 20-mesh screen and working it into 



fOFKKV AND TUTTl.l-:: I'OT TKSTS W III I KIIK'I' 1 1. 1 ZKRS I3I 

the first few iiiclics of the surface soil with a sj)atula. J he ferti- 
lizers were apphed by reinovini;- about i inch of (he surface soil and 
luixiui;- the fertilizer witli it by rolliu^- on «;laze(l paper, 'i'his soil 
was theu spread evenly over the surface of the pot and harrowed in. 

Wheat Used as Indicator. 
As wheat has shown a very marked difference in its response to 
the different fertilizer treatments in the fields and as it grows well 
under greenhouse conditions, this crop was selected for the experi- 
ment. It was sown in three parallel rows, about 30 to 35 seeds 
being used in each pot. After the plants were well started they were 
thinned to 25 per pot, care being taken to leave uniform plants. 

Shall the Crop be Matured? 

When this work was begun, it was planned to grow the crop to 
maturity, but insects and fungi attacked the first plants so severely 
that it was necessary to harvest the crop when the plants were about 
one month old. However, the various treatments already showed 
such differences that it was decided to air-dry and weigh the plants 
from each pot. The relative fertilizer requirements of this soil, as 
indicated by these results, corresponded so nearly with the field 
trials that another test was made on the same soil, but without grow- 
ing the crop to maturity. Again the indications were very similar to 
those shown by the field trials, and no attempt has since been made 
to mature the crop, it being harvested when about one month old. 

That the use of this short period of growth is permissible is sub- 
stantiated by field observations. It has frequently been noted at the 
Ohio stations that those plots which produce the largest yields indi- 
cate this by a larger growth when the crop is still young. Dr. 
Wheeler states that " The more common experience of close observers 
is to the effect that if slight soil deficiencies or faults exist, the 
plants are likely to show them even while they are very young and 
that the relative differences remain much the same until maturity."^ 
Many similar citations could be given. The results of these tests 
and the field trials, as can be seen from the data which follow, agreed 
in regard to the element most needed by all three soils and also gave 
a very good indication of the relative effects of the other two ele- 
ments. Since the object of this work was to test the value of the 
pot method as a rapid means of determining the fertilizer require- 

3 Wheeler, H. J., Brown, B. E., and Hogenson, J. C, A Comparison of Re- 
sults Obtained by the Method of Cultures in Paraffined Wire Pots with Field 
Results on the Same Soil, R. I. Agr. Expt. Sta. Bui. No. 109, p. 16. 



132 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



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133 



nicnts of soils, it ihcrcforo hardly scciiis .'uKisaMc to take the addi- 
tional time and tronhlc to i^row the crop to niatnrity, at least in the 
case of wheat. However, it is ])nrposed to investij^ate this (jucstion 
further in order to determine definitely this point. It is helieved 
that a direct comparison of pot to field results furnishes the most 
rigid and reliahle test of the value of this or any other method. 

Rksults of Pot and Field Studies. 

Two tests, usin<^ different lots of soil, have been made on the 
Wooster soil, and one each on the Strongsville and Carpenter soils. 
In every test the same kind and quantity of fertilizer per acre was 
used in the pots as was applied on the wheat crop in the field. 

At Wooster and Strongsville, which have received similar treat- 
ment, all three elements are used alone, in combinations of two, and 
all three together. These include plots 2, 3, 5, 6, 8, 9, and 11 of 
the 5-year rotation. The quantities of fertilizers per acre used on 
wheat, either alone or in combination, were 160 pounds of acid phos- 
phate, 100 pounds of potash, 120 pounds of nitrate of soda, and 50 
pounds of dried blood. In addition, 2,000 pounds of lime or 4,000 
pounds of ground limestone per acre were added. 

On the plots at Carpenter, nitrogen and potash are not used alone, 
but they were in the pots. The quantity of fertilizer applied is also 
dift'erent from that used at Wooster and Strongsville, being 120 
pounds of acid phosphate, 20 pounds of muriate of potash, 60 pounds 
of nitrate of soda, and 30 pounds of dried blood. Here 2,000 pounds 
of Hme was added. 

Table i presents the actual yield of each pot and the average in- 
crease or decrease resulting from each treatment, as compared with 



s 
















/a 

























\ 

L 
















-% 

i 












r Sn 


^O/VGSV/L 















/ 


/ 


V ^ 


P /£ 


K /V 


^ A'/ 







Fig. 5. Relation between yields of plots and pots. The solid lines represent 
the yields of plots and the broken lines the yields of pots. 



134 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



the average of the untreated pots. The probable errors given have 
been calculated according to the method of least squares. 

The average increase or decrease produced by each treatment in 
the pots and that resulting from the same treatment on the plots is 
shown in Table 2. A comparison of these data is shown graphically 
in figure 5. No curves have been made of the Carpenter results, 
since nitrogen and potassium were not applied alone on the plots. 



Table 2. — Increases Obtained from Fertilizers on Plots and in Pots. 





Field Test.l 




Fertilizer Applied. 






Pot Test, Grams. 












Grain, Bushels. 


Straw, Pounds. 






Wooster Soil 




P 




734 ± 59 


.46 dr.IO 




1. 01 ±.2 


149 ± 34 


.22 ±.l6 


N 


i.87±.2 


321 ± 43 


.i4±.07 


NP 


i3.i7±-9 


i,376± 90 


1. 21 ±.08 




8.76'±.6 


800 ± 77 


1.69 ±.05 


NK 


2.67±.2 


345 ± 40 


.32db.II 


NPK 


15-93 ±-9 


1,806 d=IOO 


i-55±-23 




Strongsville Soil * 




P 


6.58±.50 


603 ± 64 


4.i3±.05 


K 


-.33 ±-20 


— 69± II 


.82±.i7 


N 


.00±.22 


7± 24 


.74 ±.03 


NP 


9-54±-56 


876± 23 


5.04±.i6 


PK 


7.47 ±.40 


577± 41 


4.30d=.o8 


NK 


i.50±.34 


i84± 43 


•39±.07 


NPK 


9-25 ±.59 


947 ± 73 


3.94±-25 




Carpenter Soil 




P 


4-64±-3 


485 ± 50 


2.7 ±.03 


K 


No plot 


No plot 


.6 ±.03 


N 


No plot 


No plot 


.2 ±.00 


NP 


6.io±.7 


708 ± 74 


2.5 ±.i6 


PK 


6.52±.4 


668 ± 52 


1.9 ±.i8 


NK 


2.07±.4 


200± 34 


.6 ±.i8 


NPK 


9. II ±.6 


983 ± 99 


2.9 ±.i8 



^ Wooster soil, 20-year average ; Strongsville soil, 18-year average ; Car- 
penter soil, 9-year average. 



While the effects of the different treatments in the pots do not 
always correspond exactly to those in the field, there is a striking 
similarity in the trend of the curves. The most apparent variation is 
in the effect of PK on the Wooster soil. 

In the interpretation of the results of fertilizer studies it should be 
kept clearly in mind that the fundamental object is to determine the 
need of a soil for the different elements. While Table 2 and the 
curves which accompany it show the relation of one treatment to 



C'OFFl-.V AND TUTTl-K : I'OT TI'.STS WITH !• I:RTI r,lZi:KS 



another, ihcy do not develop in detail the elVeet vvhieh .'in element 
has when nsed in eonihination with the other elements. This may be 
shown hy a method of ditTerenees, which thouj^^h evidently empirical 
is of i^reat valne in estimatinj^ the true effect of an element. Table 3 
has been formed in this way from the data in Tabic 2. It shows the 
effect of the elements when used alone and in combination, both on 
the plots and in the pots. 



Table 3. — Increases of Wheat from Elements (N, P and K) Alone and in 
Combination on Plots and in Pots. 





Wooster. 


Strongsville. 


Carpenter. 


Plots. 


Pots. 


Plots. 


Pots. 


Plots. 


Pots. 




Bushels, 


Grams. 


Bushels. 


Grams. 


Bushels. 


Grams. 


Nitrogen: 
















1.87 


0.14 





0.74 




0.2 


NP-P 


5-59 


•75 


2.96 


.91 


1.46 


— .2 


NK-K 


1.66 


.10 


1.83 


-•43 




.0 


NPK-PK 


7.17 


-.14 


1.78 


-•36 


2.59 


I.O 


Average 


4.07 


.21 


1.64 


.21 




•25 


Phosphorus: 














P alone 


•7-58 


.46 


6.58 


4-13 


4.64 


2.7 


NP-N 


11.30 


1.07 


9-54 


4^30 




2.3 


PK-K 


7-75 


1-47 


7.80 


3^48 




1-3 


NPK-NK 


13.26 


1.23 


7.75 


3^55 


7.04 


2.3 


Average 


9-97 


1.06 


7.92 


3^86 




2.15 


Potassium: 














K alone 


1. 01 


.22 


-•33 


.82 




.6 


NK-N 


.80 


.18 


1.50 


-•35 




•4 


PK-P 


1. 18 


1.23 


.89 


.17 


1.88 


-.8 


NPK-NP 


2.76 


•34 


•49 


— 1. 10 


3.01 


.4 


Average 


1.44 


.47 


.64 


— .11 




•15 



From Table 3 it is apparent that, no matter hov^^ the effect of the . 
elements is measured, on all the soils studied phosphorus has always 
given the largest increase and is consequently the element most 
needed. In this important fact the pots and plots agree. 

In regard to the relative need of potash and nitrogen at Wooster 
the plots and pots do not agree. The latter indicate a lower require- 
ment for nitrogen than for potassium, while the opposite is true in the 
field. This apparent contradiction is believed to be due to the fact 
that the soil used in the pots at Wooster was taken from under sod 
and therefore probably contained more nitrogen than the long culti- 
vated plots. In this connection it might be noted that out of the 
20 crops of wheat at Wooster potash has produced a greater increase 
than nitrogen in seven different seasons, or the chances are practically 
2 to I in favor of nitrogen. 

The Strongsville results show a close agreement, the average effect 



136 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



of each element as determined in Table 3 indicating the same as the 
field trials. They also show that phosphorus, as compared to nitrogen 
and potassium, has given a greater increase than at Wooster. This 
is also indicated in the fact that the 18-year average at Strongsville 
shows no effect from nitrogen and a decrease of only 0.33 bushel 
from potassium, which emphasizes the small need of this soil for 
either of these elements. 

It must be remembered that the wheat on the plots is in a 5-year 
rotation and is preceded by corn and oats, each of which is fertilized. 
In the pots wheat is the only crop grown, therefore any residual 
effect due to the fertilization of previous crops is not present. When 
this and other factors previously mentioned are considered, the agree- 
ment between the field and pot results as to the relative need of the 
soil for the different elements is remarkably close. In fact, it is 
closer than that between different sections in the field, as may be seen 
by comparing the data in Table 4 with that in the previous tables. 
As wheat on the plots is grown in a 5-year rotation, at the end of 
20 years it has appeared four times on each section. The figures 
given in Table 4 represent the average yields and increases of these 
four crops on each section at Wooster. 



Table 4. — Average Yields and Increases'^ of Wheat in 5-Year Rotation at 
Wooster by Sections for 20-Year Period. 



Average Yields in Bushels, 4 Cropc 



Average Increases in Bushels, 4 Crops. 



Treatment. 


A 


B 


C 






A 


B 


c 




E 


Check 


10.97 


20.89 


4-34 


8.26 


10.37 












P 


18.67 


24.09 


13.09 


17-65 


19.25 


6.II 


4.24 


8-94 


9-65 


8.94 


K 


17.72 


18.66 


3-96 


7.88 


II. 71 


3-57 


- .14 


.005 


.12 


1.49 


Check 


15-74 


17.76 


3-76 


7.51 


10.16 












N 


16.92 


20.92 


5-44 


8.35 


12.52 


1.72 


2.96 


1. 71 


.66 


2-33 


NP 


23-39 


32.35 


17.16 


21.83 


25-74 


8.72 


14.17 


14.70 


13.96 


15-51 


Check 


14-13 


18.38 


3-67 


8.04 


10.26 












PK 


21.27 


24.19 


13-73 


19.52 


42.59 


7.50 


5-15 


9.90 


11.30 


10.04 


NK 


17.04 


23.24 


4.96 


11.05 


12.00 


3.63 


3-54 


.79 


2.65 


2-74 


Check 


13.04 


20.35 


4.42 


8.57 


8.56 












NPK 


25-59 


38.21 


18.50 


25-^5 


26.86 


12.06 


18.28 


14.46 


16.57 


18.27 



1 The method of calculating increases is explained by Dr. Chas. E. Thorne, 
as follows : " In all these experiments with fertilizers and manure every third 
plat is left untreated, as a check plat, and the increase for each treated plat is 
found by comparing its yield with that of the untreated plats between which 
it lies. In calculating increase it is assumed that if the yield of Plat i, for 
.example, were 30 bushels, and Plat 4, 33 bushels, that of Plat 2, had it not been 
manured, would have been 31 bushels, and that of Plat 3, 32 bushels." Ohio 
Agr. Expt. Sta. Bui. 184, p. 229, 1907. 



COFI'KV AND TUTTLK: I'OT TESTS WITH K i: UT! LI ZKKS 



An oxaniiMation of these data will show that the yields and in- 
creases from l,he same treatment vary i;reatly on the diflercnt sec- 
tions, due ])rimarily to soil and seasonal di iTerenees. While it is 
seen that all sections, like the pot tests, show a i,n-eater response to 
phosphorus than to nitroi^en or potassium, there is a considerahle 
variation in the response to either of the last two elements or the 
various comhinations in which they appear. Section 1), which has 
given the greatest increase from P, has given the least increase from 
N and very little from K ; Section B, which has given the least re- 
sponse to P, has given the greatest response to N and has shown a 
decrease from K; wdiile Section A, which shows the smallest increase 
from NP of all the sections, shows the largest increase from NK. 
Although these variations between the different sections occur, the 
indications, as to their relative need for the different elements, are 
the same, with the exception of Section A, where the plot receiving 
potassium alone has given an abnormal yield, which Director Thorne 
states is probably due to some previous treatment of the land. 

Pot Work at Other Stations. 
In connection with this work a circular letter was sent to every 
experiment station in the United States, requesting information con- 
cerning their experience with fertilizer pot work. As several sug- 
gested that a report of this information be published, it is summarized 
herewith. 

Replies were received from 41 stations, of which only 14 reported 
pot work with fertilizers, while 3 stated that they used outdoor cylin- 
ders. Many of the western stations state that as yet soil fertihty is 
not a prominent question. 

The size of the pots used varied from i to 6 gallons, with the 
majority preferring a 4-gallon to 6-gallon pot. 

Surface soil only is used by 7 stations ; both surface and subsoils 
by 4 ; while 3 report that as a rule they use only the surface, but 
occasionally both. Those that reported cylinders use both surface 
and subsoil. 

Some of the replies stated that duplicate pots were used, and a few 




reported using triplicates. While every report did not cover this 
point, it is assumed that all carry on their tests in duplicate at least. 

In regard to mixing and potting the soil, the stations which reported 
successful pot studies do not dry or excessively handle the soil by 
pounding, fine screening, etc. 

A few stations reported trouble with pots drying out. It is to be 
noted that these used surface soil only. 



138 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

Commercial fertilizers were used except in a few cases where c. p. 
salts were necessary. 

Every station reports that a shght excess of seed is sown and that 
the plants are thinned to the same number per pot. All based their 
conclusions on the dry weight, while a few record the green weight 
also. 

While a few state that they have compared their results with field 
trials, apparently none have compared their data with long-time field 
experiments. It is evident that the object of many of the studies has 
been to question the availability of certain fertilizers rather than to 
determine the relative need of the soil for the principal plant foods. 

Among the stations which report success with fertilizer pot studies, 
it is the consensus of opinion that if one element is needed the pot 
test is quite reliable in indicating it, while if two or more elements 
are lacking the pots may differ from field indications. 

Conclusions. 

From the data presented in this paper and from the experience at 
other stations, it would appear that the best results may be expected 
if the following suggestions are adhered to rather closely in carrying 
on pot work : 

The soil should be gotten into the pots in as nearly the same relative 
position and condition as in the field. Both soil and subsoil should 
be used, the surface soil being taken to the depth at which the most 
marked change takes place, usually about the depth to which it is 
plowed. 

Air-drying and excessive handling should be avoided. The soil 
should be settled to as nearly field condition as possible. Water has 
been used very satisfactorily for this purpose in the work reported in 
this paper. 

The same fertilizer apphed in practice has generally been used and 
is mixed with the first 3 or 4 inches of soil. It is beHeved best to 
simulate field practice as nearly as possible. 

A somewhat larger quantity of seed per acre should be sown and 
the plants thinned to about the same number per acre as in the field 
and to an equal number per pot. 

While most stations have grown the plants to maturity, the results 
secured here seem to show that with wheat a period of one month 
to six weeks is sufficient to indicate the relative fertilizer need of the 
soils studied. 

The dry weight is considered most reliable. 



coFFi-: V A N 1 ) r u TT LI-:: P( ) r ti^sts w i t i r i- 1-: irr i u z i-: k s 



139 



The tests should he made in not less than trij)hcates and statistical 
methods should he applied. 

These fertilizer pot tests have heen interpreted from the stand])oint 
of the relative need of the soil for the diilerent elements. y\s a com- 
parison of the results of the pot tests and field trials made in this way 
agree very closely, it seems that pot tests may he of very j^^reat 
value in helping to solve this very imj^ortant question. By their use 
it should he possihle to ohtain data which would enable one to de- 
termine with considerable accuracy about what treatment most prob- 
ably will g'ive best results, and this treatment can then be tried along 
with others in the regular field trials. It will then be possible to see 
whether the indications secured in the pots apply in actual field trials, 
as has been true in the case of the soils reported upon in this paper. 



VARIATIONS IN SOY BEAN INOCULATION.^ 

John H. Voorhees. 

During the summer of 1913 a number of cooperative tests were con- 
ducted to determine the growing period of several varieties of soy 
beans in different parts of New Jersey. Observations made on the 
inoculation of different varieties on the farm of Dr. D. H. McAlpin, 
Morris Plains, N. J., brought out some interesting points that seem 
worthy of special mention. 

The test at this place was conducted on a well-drained, medium- 
heavy clay loam soil. Oats and field peas had been grown the previous 
year upon a well-manured and fertilized corn stubble. This crop was 
harvested for hay and a cover crop of rye and hairy vetch planted. 
The cover crop was plowed under during the early part of May and 
the soy beans planted during the first week in June. One-acre plats 
were sown to each of the following varieties : Mikado, Peking, 
Haberlandt, Tarheel Black (Black Shanghai, S. P. I. No. 14952), 
Brown (Trenton, S. P. I. No. 24610), and Auburn. Each field was 
divided lengthwise into two parts, " nitrogerm " being used on one and 
farmogerm " on the other. Two rows in the center of each plat re- 
ceived no treatment, thus separating the two kinds of inoculation. 
All varieties germinated well and made splendid growth. 

In observations made June 25 the plants of all varieties bore root 
nodules except the Haberlandt, which seemed to lack them entirely. 

^ Received for publication December 5, 1914. 



140 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



On September 8 the nodules on the Mikado were very numerous, 
spreading around the tap root in a close mass, this also being true to a 
less extent with the Auburn and Brown varieties. The Tarheel Black 
had a few large nodules scattered on the finer roots as far as 8 to 12 
inches from the tap root. The Peking had a moderate number of 
medium-sized nodules located from 3 to 4 inches from the tap root. 
No nodules, however, were found on the Haberlandt. In two rows 
where the Brown and Haberlandt varieties were mixed in planting, 
the root systems became rather closely associated. After separating 
the roots of the two varieties, it was found that the Brown variety had 
numerous nodules scattered throughout, but no nodules were found 
on the roots of the Haberlandt. In all over one hundred plants were 
examined and the same conditions found in each case. It is quite 
evident that nodule bacteria capable of inoculating the Brown variety 
were present in the plat, but that the same bacteria did not cause 
nodules to form on the Haberlandt. 

In ascribing a reason for the lack of inoculation on the Haberlandt, 
it is the writer's opinion that dif¥erent varieties of the same legume 
bear different and definite powers of resistance to association with 
symbiotic bacteria. An alternative suggestion by Dr. Mel. T. Cook 
of this station, is that the association of nodule bacteria with legumes 
really causes a disease, the harmful effects of which are overcome by 
the benefit obtained through the addition of nitrogen to the food 
supply of the plant. 

It was the writer's desire to continue the experiment in 19 14, re- 
versing the direction of the rows, but unfortunately he was unable to 
continue the work. The results obtained are given with the hope that 
they may be used by some other worker. New Jersey Experiment 
Station, New Brunswick, N. J. 



Some similar results concerning variation in soy bean inoculation were noted 
at the West Tennessee Experiment Station at Jackson, in the season of 191 1- 
In 1910 Mr. S. A. Robert, superintendent of the station, observed that the Acme 
and Tokio varieties of soy beans lacked root nodules, while the Mammoth, 
planted under the same conditions, produced many of them. The next season, 
191 1, the Mammoth, Acme, and Tokio were planted in a field where the Mam- 
moth had been grown in 1910 and where it was well supplied with nodules. In 
the latter part of September the writer had occasion to examine a large number 
of plants of these three varieties and in no case were nodules found on plants 
of the Acme and Tokio varieties, while the plants of the Mammoth had numer- 
ous nodules. In the varietal tests conducted at Arlington Experimental Farm, 
Virginia, for a number of seasons, the Haberlandt was as well supplied with 
nodules as most of the other varieties. — W. J. Morse, U. S. Department of 
Agriculture. 



ACKONOM IC AI' I AI US 



141 



AGRONOMIC AFFAIRS. 

MEETINGS OF THE SOCIETY. 

The attention of nicnil)crs of the American Society of A<^rononiy 
is a.qain called to the two meetings of the society which are to he held 
within the next few months. The first, a joint meeting with the 
Great Plains Cociperative Association, will he held at Mandan, N. 
Dak., on July 14-16. The second, the annual meeting of the society, 
will he held at Ikrkeley, Cal., August 9 and 10. At the same time, 
the American Farm-Management Association and the Society for 
the Promotion of Agricultural Science will hold their sessions. On 
August 11-13 the Association of American Agricultural Colleges 
and Experiment Stations will meet at Berkeley. Memhers who ex- 
pect to present papers at either the Mandan or the Berkeley meeting 
are urged to send the titles to the secretary of the society, so that the 
programs can be prepared well in advance of the meetings. Papers 
for the Mandan meeting should have a bearing on some agronomic 
problem in the Great Plains area. 

MEMBERSHIP CHANGES. 

The total membership reported in the previous number of the 
Journal was 438. Since that time, 26 new members have been re- 
ceived and 3 members have resigned. On March 31, according to 
the constitution of the Society, those whose dues for 19 14 were still 
unpaid automatically lapsed. Twenty-four such lapsed members are 
reported herewith. This is the largest number of lapsed members 
yet reported; on the other hand, the accession of new members has 
been more rapid in 1915 than ever before. The total for the year so 
far, 71, just equals the largest number of new members previously 
added to the Society in any one entire year. The total number of 
new members for 19 15 should not be less than 100. The net mem- 
bership of the Society at this date is 437. The names and addresses 
of new members, the names of those who have resigned or lapsed, 
and the changes of. address are as follows: 

New Members. 

Bancroft, Ross L., Iowa State College, Ames, Iowa. 
Benton, T. H., Iowa State College, Ames, Iowa. 



142 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



BoLLAND, Jens, Box 242, South Dakota State College, Brookings, S. Dak. 

Carnes, Homer M.. 728 14th St., Corvallis, Ore. 

Cook, I. S., Jr., College of Agriculture, Morgaiitown, W. Va. 

Dean, H. K., Umatilla Experiment Farm, Hermiston, Ore. 

Dorsey, Henry, College of Agriculture, Morgantown, W. Va. 

Forman, L. W., Iowa State College, Ames, Iowa. 

Hanson, H. P., Old Agrl. Hall, Iowa State College, Ames, Iowa. 

Jensen, L. N,, Cereal Field Station, Amarillo, Texas. 

Kemp, W. B., College of Agriculture, Morgantown, W. Va. 

Kinney, H. B., Iowa State College, Ames, Iowa. 

Krall, John A., Iowa State College, Ames, Iowa. 

Lechner, H. J., Iowa State College, Ames, Iowa. 

Leth, Robert J., University of Idaho, Moscow, Idaho. 

Maughan, Howard J., Experiment Station, Logan, Utah. 

Olson, P. J., University Farm, St. Paul, Minn. 

Potter, Ralph S., Iowa State College, Ames, Iowa. 

Reed, H. R., Yuma Field Station, Bard, Cal. 

Reid, Harold W., Iowa State College, Ames, Iowa. 

Reinholt, Martin, Agricultural College, N. Dak. 

Simard, J. A., Box 211, Quebec City, Quebec, Canada. 

Stewart, Geo., Dept. Agron., Agricultural College, Logan, Utah. 

Stoa, Theodore E., Agricultural College, N. Dak. 

Thomas, Melvin, Agricultural College, N. Dak. 

Wentz, John B., Bellefourche Expt. Farm, Newell, S. Dak. 



Edward C. Johnson, 

Basil M. Benzin, 
J. Stanford Brown, 
Alex. Carlyle, 
George Dunlop, 
Robert J. Evans, 
W. H. Frazier, 
L. F. Gieseker, 
Leonard Hegnauer, 



Members Resigned. 
Edward R. Minns, 

Members Lapsed. 
E. L. Hsieh, 
Thomas F, Hunt, 
T. E. Keitt, 
Franz E. F. Krause, 
J. G. Lill, 
R. S. Mackintosh, 
C. F. Marbut, 
P. E. Miller, 



A. L. Thompson. 

J. M. Napier, 
A. W. Palm, 
W. R. Porter, 

F. C. QUEREAU, 

J. H. Reisner, 
H. M. Sanderson, 
C. G. Selvig, 
Satyosaran Sinha. 



Addresses Changed. 
Ball, Wilbur M., care Director E. D. Ball, Logan, Utah. 
Bower, H. J., Agricultural College, Manhattan, Kans. 
Coffey, G. N., University of Illinois, Urbana, 111. 
Deatrick, Eugene P., 708 E. Seneca St., Ithaca, N. Y. 
EwiNG, E. C, Scott, Miss. 

Olson, M. E., Soils Section, Iowa State College, Ames, Iowa. 
Young, Yungyen, Nanyang Middle School, Shanghai, China. 



AGRONOMIC AKKAIKS 



NOTES AND NEWS. 

A. T. Anders, a scientific assistant in the office of cotton breeding, 
U. S. Department of Agriculture, died suddenly in Washington, D. C, 
on April 3. Mr. Anders had undergone an operation for appendicitis 
a few days previously and was apparently recovering rapidly, when 
heart failure caused his death practically without warning. 

Knute Espe has been appointed an assistant in soil survey work at 
the Iowa station. 

E. C. Ewing, formerly head of the department of cotton breeding 
at the Mississippi station, is now in charge of the experimental de- 
partment recently established by the Mississippi Delta Planting Co. at 
Scott, Miss. H. B. Brown, formerly professor of botany and forestry 
of the Mississippi college, has succeeded Mr. Ewing in the cotton 
work at the station. 

Walter L. Latshaw has been appointed assistant in soil analysis at 
the Kansas station. 

E. R. Lloyd, director of the Mississippi station, also has been made 
director of extension work. J. R. Ricks, agronomist, has been made 
vice-director in addition to his other duties. 

Yungyen Young, who has been pursuing post-graduate studies at 
the University of Illinois, has been recalled to his native country, 
China. He is now located at the Nanyang Middle School, Shanghai. 

Recent changes and appointments in the office of cereal investiga- 
tions, U. S. Department of Agriculture, include the transfer of T. R. 
Stanton, formerly assistant in cereal investigations on the Arlington 
Experimental Farm, to be assistant in oat'^'investigations with head- 
quarters at Washington, D. C. ; A. D. Ellison, to the Arlington 
Experimental Farm ; vice T. R. Stanton ; J. W. Jones, to the Nephi 
substation, Nephi, Utah, vice A. D. ElHson ; and the appointment of 
V. H. Florell as scientific assistant at the Cheyenne Experiment 
Farm, Archer, Wyo., vice ]. W. Jones. 

The second Pan-American Scientific Congress will hold its sessions 
in Washington, D. C, December 27, 1915, to January 8, 1916. A 
wide range of scientific subjects will be discussed by the nine sec- 
tions of the congress. Section III, Conservation of Natural Re- 
sources, Agriculture, Irrigation, and Forestry, and Section IV, Edu- 
cation, are of particular interest to members of the American Society 
of Agronomy. The members of the congress consist of (i) the 



144 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 

official delegates of the countries represented; (2) representatives of 
universities, institutes, societies and scientific bodies; and (3) indi- 
viduals who may be invited by the executive committee. The pre- 
liminary program may be obtained from Mr. William Phillips, Third 
Assistant Secretary of State, Washington, D. C, who is chairman of 
the executive committee. 

Meeting of the Washington Section. 
The eighth regular meeting of the Washington (D. C.) Section of 
the American Society of Agronomy was held at the Cosmos Club on 
March 9, 191 5, with an attendance of about 40 members and guests. 
Dr. W. W. Stockberger presented an interesting illustrated statistical 
paper entitled "Variation in Plat Yields of Hops." In this paper, 
the yields of individual hop plants in a field in California for a series 
of years were tabulated in dififerent groups. The object of the tabula- 
tions was to determine whether or not individual variations were con- 
stant from year to year and also to determine the variations in yield 
in different parts of the field preliminary to starting some fertilizer 
tests. " Natural Wheat-Rye Hybrids " was the title of a brief paper 
by Dr. C. E. Leighty, in which illustrations and descriptions of an arti- 
ficial and several natural wheat-rye hybrids were presented. Dr. L. J. 
Briggs, who attended the meetings of the British Association of 
Science in Australasia last summer, talked on " Some Phases of Agri- 
culture in New Zealand." Numerous excellent views of field and 
pastoral scenes in New Zealand were shown, and much interesting 
information wa^ given regarding agricultural conditions there. 

Department of Agriculture Appropriations for 1916. 
The appropriation act fbr the Federal Department of Agriculture 
for the fiscal year beginning July i, 191 5, carries a total of $22,971,- 
782, an amount $3,105,950 in excess of the appropriation for the 
previous year. The new appropriation, however, contains a provision 
for an emergency fund of $2,500,000 for fighting contagious diseases 
of animals (foot-and-mouth disease, rinderpest, etc.), which has not 
previously been included, so that the actual increase is only $605,950. 
The total appropriation just named, however, does not include the 
$1,080,000 available under the Smith-Lever act for agricultural ex- 
tension, the permanent annual appropriation of $3,000,000 for meat 
inspection, or the $500,000 for the publication of bulletins and reports. 
The bill makes provision for the reorganization of the Department's 
activities as outlined in an earlier number of the Journal. 



JOURNAL 

OF TIIK 

American Society of Agronomy 



Vol. 7. July-August 1915. No. 4. 



A COMPARATIVE STUDY OF THE EFFECT OF CUMARIN AND 
VANILLIN ON WHEAT GROWN IN SOIL, SAND, AND 
WATER CULTURES/ 

Jehiel Davidson, 

Cornell University, Ithaca, N. Y. 

(Contribution from the Department of Soil Technology, Cornell University.) 

The Present Status of the Theory of Soil Toxicity. 

Introduction. 

The theory of soil toxicity dates from the time of De Candolle. 
Believing that the experiments of Macaire,^ which were carried out 
at his suggestion, proved that plant roots secrete under normal condi- 
tions certain organic substances, which in the case of the bean were 
found to be harmful to the plant that produced them but beneficial to 
other plants, De Candolle came to consider these root secretions of 
universal significance in practical agriculture. He proposed to ex- 
plain the necessity for crop rotation as based on the fact that plants 
excrete through their roots certain substances that are deleterious to 

1 A thesis submitted to the faculty of the Graduate School of Cornell Uni- 
versity in partial fulfillment of the requirements for the degree of Doctor of 
Philosophy by Jehiel Davidson, B. Sc. Ithaca, N. Y., June, 1914. Received 
for publication March 30, 1915. 

- Macaire, Memoire pour Servir a L'Histoire des Assolemens, Ann. de Chim. 
et Phys., 52 (1833). p. 225-240. De Candolle, A. P., Physiologic Vegetale, 
p. 248-251. Paris, 1832. 

145 



146 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



the same plants or their near relatives, but which are beneficial to 
Other plants more or less distantly related to them.^ 

Liebig* considered De Candolle's theory of crop rotations " as rest- 
ing on a firm basis " and placed full reliance in the experiments of 
Macaire. Although he interpreted the views of both of them in the 
light of his favorite plant-food theory, he considered the conversion 
of the injurious excrements of plants into humus as a matter of 
great importance to soil fertility. 

The experiments of Macaire which constituted the principal evi- 
dence in favor of harmful root secretions, as well as of root secre- 
tions in general, were proved to be erroneous by Braconnot^ and 
others, and De Candolle's views lost their adherents and were for- 
gotten under the dominance of Liebig's mineral theory. 

The theory of soil toxicity has been brought to the front again by 
the Federal Bureau of Soils. It has been modified and broadened. 
Harmful root excretions and toxic organic substances in general ac- 
count, according to their views, not only for the inability of a soil to 
grow the same crop successively for a number of years, but also 
for the infertility of poor soils in general. They oppose the theory 
of soil toxicity to Liebig's mineral theory, which in its principal 
features still has a hold on the minds of the majority of agricultural 
investigators. To these investigators, plant food, whether of min- 
eral or of organic origin, whether produced by physical, chemical or 
biological agencies, whether found in the soil originally or introduced 
in the form of manures and fertilizers, is still the principal key to 
soil fertility. 

Character of the Evidence in Favor of the Theory of Soil Toxicity. 

The investigators in the Bureau of Soils have brought forward a 
considerable amount of evidence in support of their views. The evi- 
dence may be divided in two groups. One follows the trail of De 
Candolle and deals with root secretions, the other deals with the- 
presence in the soil of toxic organic substances in general. It is all, 
however, of indirect nature and, like all indirect evidence, it holds 
good only so long as the phenomena on which it is based can be ex- 
plained only by the theory which it supports. 

3 De Candolle, 1. c., pp. 1474-75 and pp. 1493-1520. 
Liebig, Justus, Chemistry in its Application to Agriculture and Physiology, 
p. 163-174. Cambridge, 1842. 

^ Braconnot, H., Recherches sur I'lnfluence des Plantes sur le Sol, Ann de 
Chim. et Phys., 62 (1839), p. 27-40. 



I) wiDsoN : i:fi'i:ct oi-' cumarin and vanillin on \viii;ai. 147 



Anv oilier cxplan.ilion which could he olTcrt'd to accouiil for the 
phenomeiKi that serxi- as evidence in favor of the theory of soil 
toxicity would roh the evidence of its principal force and relegate the 
theory in ([uestion to a mere hypothesis, more or less i)lausil)le. Tt 
remains to he seen whether the evidence 1)rou^ht forward stands the 
criterion of indirect evidence, that is, whether the phenomena on 
which it is based can not he explained in any way except by the 
theory of soil toxicity. 

Crop Rotations. 

No new evidence has been broug^ht forward since the time of De 
Candolle to substantiate the view that the failure to ^row one crop 
successfully year after year is due to autotoxic substances secreted 
by the plant roots. The experiments of Macaire which formed the 
principal basis of De Candolle's theory, as stated above, have been 
found to be entirely erroneous. The experiments at Rothamsted^ 
where wheat was grown successfully for fifty years in succession 
would tend to serve as evidence against the secretion of autotoxic 
substances by the roots. Up to the present time no root secretions 
except carbon dioxide have been definitely established. 

Passing from facts to general considerations, we can easily come to 
the conclusion that autotoxic excreta in plants are inconsistent with 
the general laws of adaptation. We could conceive of excreta which 
are harmful to other plants as a weapon in the struggle for survival, 
as was suggested by Humboldt and Plenk^ with reference to the 
existence of plant associations. It is hard, however, to conceive how 
an autotoxic excretion helped the plants possessing it to survive in 
the struggle for existence or at least how it did not interfere with 
them in this struggle. 

As to the explanation of the beneficial efifects of crop rotations, 
there are a great number of other factors besides autotoxic secreta 
which may account for them. These include the different methods 
of cultivation associated with the different crops in the rotations, the 
different methods of feeding, the difference in the microbiological 
flora which accompanies the different crops, etc. 

Effect of Grass on Trees. 

It has been observed on the Woburn Experimental Fruit Farm that 
grass was injurious to fruit trees. The effect of the grass was so 

^ Gilbert, J. H., Agricultural Investigations at Rothamsted, U. S. Dept. Agr., 
Office of Exp. Sta. Bui. 22, p. 146-171. 
^ De Candolle, 1. c, p. 1474-76. 



148 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



singular in its character that, according to the authors of the reports, 
every tree which was grassed over could be easily recognized even 
if the surface soil were entirely hidden from view. 

" The coloring matters in the leaves, bark and fruit are affected in a manner 
which is not produced by any other form of ill treatment. The bark is pale 
and much yellower than in a healthy tree ; the buds burst at a comparatively 
early date ; and the foliage always exhibits a pale sickly hue, which is quite 
different from that of trees in the open ground. The autumn tints appear some 
two weeks earlier than in healthy trees. The fruit, when there is any, shows 
similar peculiarities of coloring; in case of green apples, for instance, the color 
is changed either to waxy yellow or to brilliant red."^ 

The ill efTects of the grass were shown with reference to old trees 
as well as to newly planted trees. The efifects on the latter were in 
many cases fatal, leading to death after the first season. 

The possible reasons for the ill effects of the grass that suggested 
themselves were deficiency in moisture due to excessive loss of water 
caused by transpiration from the grass, deficiency in plant nutrients 
due to competition of the grass, lack of aeration, excessive amounts of 
carbon dioxide due to respiration of the grass roots, and differences 
in temperature. The authors of the reports of the Woburn Fruit 
Farm checked up the influence of every one of these factors and 
found that none of them could be considered responsible for the 
characteristic ill effects on the trees produced by the grass. They 
therefore reached the conclusion that the effect of the grass was due 
to some direct poisonous action produced by the grass, either through 
the agency of micro-organisms for the development of which it offers 
favorable conditions^ or directly by secreting some poisonous substance 
through the roots. 

On a closer examination, however, of the methods used in the ex- 
periments which were carried out with the object of checking up the 
individual influences of the factors mentioned above, we find that 
they were not thorough enough to justify the negative attitude of the 
experimenters toward these factors with reference to their instru- 
mentality in the ill effects caused by the grass on the apple trees. 

To check up the influence of the moisture factor, the experimenters 
supplied water artificially to the grassed-over trees and found no im- 
provement. They grew trees in closed pots with a supply of mois- 
ture limited to such an extent the trees showed signs of actual suf- 
fering from thirst, but the peculiar grass effects could not be observed, 
although the vigor of the trees was markedly impaired. They could 

8 Pickering, S. P., The Effects of Grass on Apple Trees, Jour. Royal Agr. Soc. 
of England, 64 (1903)- P- 373- 



i).wii)S()N : I'.i' I'l'.ci* oi'' ( TMAKix WD \ \\ii.i.iN' OX vviii;.\i". 149 



not observe any di ITcicmicc in [\\c a|)j)i'aianrc of llu- ^i-asscd-ovcr 
trees hclwcen dry and wcl seasons. Tlu' i^rasscd-ovcr trees never 
showed any indieation of aetnal snlTerini; from tliirst.' 

As the soil on the experimental farm was shallow, there i^ a (|Ucs- 
tion how nuieh and for how lonj; the artifieial a|)i)lieations of water 
whieh were made weekly and the rains of the wet seasons increased 
the actual moisture content of the soil. riiere is also douht as to how 
nuich of the increase was left at the (lis])osal of the trees, takinjj^ in 
consideration the fact that i^^rass is such a powerful conii)etitor for 
moisture. That the trees in the closed pots did not show the charac- 
teristic peculiarities of the grassed-over trees might he due to the 
fact that the trees in the pots show^ed actual signs of suffering from 
thirst, while the water supply of the grassed-over trees was not de- 
ficient to that extent. Would it not have been more direct to have 
grown trees in pots together \vith grass and to have had the moisture 
properly controlled by weighings at regular intervals? 

In order to check up the aeration factor, the soil under the grassed- 
over trees was aerated in various ways and the soil under trees grown 
without grass was prevented from being aerated as efifectively as ])os- 
sible. No change was observed by the experimenters in the behavior 
of the trees under either treatment. 

However, no mention is made of how effective the artificial aera- 
tion proved to be, that is, whether or not the soil air was actually en- 
riched in oxygen. It further remains questionable whether the grass 
again did not prove to be a more powerful competitor for the increase 
in oxygen, if any. With reference to the experiments in which 
aeration was prevented, it is possible that in the absence of any com- 
petition, the oxygen supplied in the water which came from aerated 
sources might have been sufficient to supply the needs of the trees. 

The plant-food factor was checked up by growing a two-year-old 
tree in washed sand which contained very insignificant amo'dnts of 
the nutrient elements. The tree made good normal growth for a 
whole year and survived during the second season without showing 
any of the characteristic grass effects. The experimenters concluded 
that the deficiency in plant food is not the factor which is responsible 
for the grass effects, since practically entire lack of plant food failed 
to produce eft'ects similar to those produced by the grass. 

There is some question, however, whether there was an entire lack 
of plant food. It is possible that the amount of plant food contained 
in the water with which the tree was supplied was sufficient to support 

9 Pickering, S. P., 1. c. 

10 Pickering, S. P., 1. c. 



I 50 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

the normal growth of a two-year-old tree for one season. It is 
further possible that the deficiency in total plant food is less injurious 
than the deficiency in one element of plant food, which might have 
been the case of the grassed-over trees. Would it not have been 
more to the point, as in the case of the moisture experiment, to have 
grown the two-year-old tree together with grass in the presence of an 
abundant supply of balanced plant food? 

The principal fallacy of the experiments, however, lies in the fact 
that the experimenters were trying to obtain the peculiar grass effects 
from each of the factors singly, while these effects might have been 
the result of certain combinations of these factors. The peculiar 
grass effects as they are described by the Woburn investigators could 
have been ascribed with a great degree of plausibility to the combined 
influence of a deficiency in moisture and nitrates. This possibility 
is strengthened by the fact that when the soil around the trees was 
planted to clover, the color effects were missing. 

The inability of oak trees to advance into the socalled " oak open- 
ings " (grassy tracts) which were found in the natural oak forests of 
Ohio and Indiana^^ and the antagonisms existing between butternut 
trees and shrubby cinquefoil, reported by Jones and Morse,^^ as well 
as the antagonism between peach trees and several grasses reported 
by Hedrick,^^ are phenomena similar to those observed on the Woburn 
Fruit Farm. Toxic excreta or poisonous action in general is not the 
only possibility which may be offered in their explanation. 

Wheat Grown in Association with Tree Seedlings. 

Germinated wheat seedlings were grown by C. A. Jensen''* m paraf- 
fined pots in association with seedlings of pine, maple, dogwood and 
cherry. The same number of wheat seedlings w^ere planted in every 
pot. Successive crops of wheat were grown one after another for 
periods of two to three weeks. One of the pine seedlings died dur- 
ing the first crop of wheat but the pot was not discarded and re- 
ceived the same treatment as the other pots. Table i (taken intact 
from Bureau of Soils Bulletin No. 40) gives the relative green 
weights of the wheat crops. 

11 Schreiner, Oswald, and Reed, Howard S., Some Factors Influencing Soil 
Fertility, U. S. Dept. Agr., Bur. Soils Bui. No. 40, p. 37. 1907. 

12 Jones, L. -R., and Morse, W. J., Ann. Rep. Vt. Agr. Expt. Sta. 16 (1903), 
p. 173-190. U. S. Dept. Agr., Bur. Soils Bui. No. 40, p. 17. 

13 Hedrick, U. P. Proc. Soc. Hort. Sci., 1905, p. 72-82. U. S. Dept. Agr., 
Bur. Soils Bui. No. 40, p. 17. 

14 Schreiner, Oswald, and Reed, Howard S., 1. c, p. 18-19. 



D.wiDSON : r ()i- cr MA KIN' and vanilmn ox vviii:\i. f l 



Taiii.i: 1. Ki'lutii i- (//(•(•;; ll 'i'i(/lits of Wheal Crol^s (in>i<'ii in . IsM't uili^'ii 
Willi Tree Seedlings. 



1 )ate of Harvesting. 


June 
ag. 


Tulv 
la. 


Aug. 
I. 


Aug. 
aa. 


Sept. 
6. 


Oct. 
13- 


Oct. 
39. 


Nov. 
19. 


Dec. 
6. 


Ave. First 
Six Crops. 




Ave. Last 
1 nree 

Crops. 


Control 


100 


100 


100 


100 


100 


100 


100 


100 


100 


100 


100 




76 


65 


86 


68 


67 


86 


92 


91 


96 


74 


93 




44 


86 


75 


59 


71 


79 


90 


75 


109 


71 


91 


" 3 


21 


83 


72 


72 


79 


84 


81 


103 


92 


70 


92 




92 


96 


76 


84 


71 


65 


85 


68 


115 


81 


89 


2 


86 


79 


63 


86 


75 


73 


84 


107 


88 


78 


93 


Chcrrv 


81 


91 


102 


91 


71 


94 


88 


102 


93 


88 


94 


Tulip 


21 


106 


62 


77 


68 


100 


77 


109 


103 


75 


96 


Pine 


55 


69 


68 


52 


54 


80 


62 


83 


60 


63 


68 




62 


96 


85 


91 


80 


89 


97 


96 


67 


84 


87 



Table i shows that the wheat crops suffered from association with 
the tree seedhngs. The depressing effects of the tree seedhngs de- 
creased toward autumn, however, as is noticeable especially when 
the last two columns are compared. 

The authors of Bureau of Soils Bulletin No. 40 believe that the 
depressing effects of the tree seedlings were due to toxic excreta pro- 
duced by their roots. They believe that this view is borne out by the 
entire behavior of the experiment. The increase of the relative yields 
toward autumn coincides with the period when the trees enter upon 
their seasonal rest and was due, according to them, to the fact that 
the toxic excreta were diminished, together with the decrease of the 
general physiological activity of the deciduous trees. The increase 
in the yield of the wheat crops grown in association with dogwood 
was less because it was the last to shed its leaves. The pot containing 
the living pine tree did not show any increase in the last three crops. 
The pot containing the dead pine gave better yields than the other 
tree pots but inferior to those of the controls. The authors argue 
that the depressing effects of the trees could not be due to depletion of 
plant food since if the trees had removed sufficient plant food to 
starve the wheat plants in the summer period, the increased yield 
toward autumn would be incapable of explanation." 

However, the figures presented in the table do not show any abso- 
lute increase in yield for the tree pots toward autumn. They only 
show that they were nearer to the yield of the controls. It is possible 
that the better crops of the controls had removed toward the end of 
the summer nearly as much plant food as the wheat crops together 
with the trees in the other pots and this is why there was less differ- 
ence in the respective yields. Supposing that the yields actually in- 
creased toward autumn, the possibility that the depressing effect of 



152 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

the trees was a plant food phenomenon is not at all excluded. The 
status of available plant food in the soil is dynamic in character. 
Plant food is continually being manufactured in the soil. The same 
decrease in the physiological activity of the trees during the period 
of rest which, according to the authors, caused a decrease in root 
excreta, also caused a decrease in plant food assimilation, and the 
increased yield of wheat in the tree pots might have been due to the 
lessened competition of the trees for plant food. 

Fairy Rings. 

This fanciful name is given to rings of grass in pastures or 
meadows which are markedly darker in color and more luxuriant in 
growth. In close proximity to the rings, on the outside, various fungi 
are always found, so that there are really two rings, a ring of grass 
and a ring of fungi. The diameter of the concentric rings increases 
every year and it is generally assumed that the smallest ring is pre- 
ceded by a single point or by a small continuous area. 

Schreiner and Reed^^ are evidently inclined to interpret this phe- 
nomenon in the sense of De Candolle's theory which Way^*^ considers 
"by far the most scientific and most intelligent solution of the ques- 
tion," but which he does not accept. The phenomenon of the fairy 
rings would just fit in De Candolle's theory. The fungi recede be- 
cause they excrete certain substances which are harmful to them- 
selves but which are beneficial to grass. The excreta beneficial to 
the grass do not extend very far and therefore the luxuriant growth 
of grass follows the fungi in the form of an inner concentric ring. 

Way ignores the fact that the fungi do not grow inside of the ring 
and tries to explain the luxuriant growth of the grass. The fungi, 
according to" Way, are good collectors of the mineral plant food ele- 
ments. When they die they fertilize the soil in the immediate vicinity 
and so cause the luxuriant growth of grass of the ring. 

The authors of Bulletin No. 40 do not concern themselves with 
the grass, but with the fact that the fungi do not grow inside of the 
ring. This fact serves, according to them, as evidence in favor of 
autotoxic plant excreta. The failure of the fungi to grow inside of 
the ring can not, they say, be due to depletion in plant food, since 
the analysis of the soil inside and outside of the rings by Law^es and 
Gilbert showed too slight differences. Inside of the ring the per- 
centage of nitrogen was 0.247 and of carbon, 2.78; outside of the 

15 L. c, p. 37- 

1'^ Way, J. T., On the Fairy Rings of Pastures, etc., Jour. Royal Agr. Soc, 
7 (1846), pp. 549-552. 



D.wiDSox : r oi' ci'MAkin .wd \ \.\ii.i.in on vviii;\r. 155 



rini; llic pcrconlai^c of iiitroj^cn was o.jSi and of carbon 3.30. 'I'hc 
anionnts of carhon and nilrooon, liowcvtM*. arc consistently liiL^luT tmt- 
sidc of the rin^ than inside. It is possible that the dilTiTenee is lim- 
ited to the available or«;anic materials on which funj^i j^^row and, small 
as it is, it niav be a factor which determines the i^rowth of the fnnf^^i. 

(iilbert'' interpreted the behavior of the <i^rass and the fnn^i in the 
fairy rings entirely in the sense of the ])lant-food theory. 

There is another objection to the use of fairy rings as evidence in 
favor of autotoxic i)lant excreta. W e are hardly justified in draw- 
ing an analogy between heterotrophic and autotrophic plants, as we 
do know for certain that the heterotrophic j^lants do excrete certain 
organic substances such as enzymes, and that these substances are 
of vital significance in the economy of their nutrition. On the other 
hand, we do not kno\v of any secretions by roots of autotrophic 
plants except carbon dioxid. 

The Diminished Yield of Succeeding Crops. 

A number of experiments with w^heat in paraffined pots were con- 
ducted^^ to show that the diminished yield of succeeding crops is due 
not to depletion of plant food but to toxic excreta produced by the 
previous crop. The crops were grown for periods of three or four 
weeks. The results show invariably that the succeeding crops were 
considerably lower than the first crops. They further show that the 
addition of fertilizers did not change to any considerable extent the 
proportional relations between the first and the succeeding crops, and 
that the addition of cowpeas and lime was more efTective than the 
addition of mineral fertilizers. 

Since young crops could not have removed sufficient plant food to 
account for the marked decline of the succeeding crop and since the 
addition of cowpeas and lime which do not furnish immediate plant 
food proved to be more effective than the addition of direct plant 
food in the form of fertilizers, the authors conclude that the depres- 
sive efifect of the previous crop was due to toxic excreta. As further 
evidence in this connection, they consider the fact that, as shown by 
their experiments, the mere germination of seeds in a soil is already 
detrimental to the succeeding crop. Similar results were obtained by 
Livingston^^ and his associates with soil and washed quartz sand. 

1" Gilbert, J. H., Note on the Occurrence of Fairy Rings, Jour, of Linnean 
Soc, 15 (1877), pp. 17-24- 

IS Schreiner and Reed, 1. c, p. 10-15. 

19 Livingston, Burton Edward, Britton, J. C, and Reid, F. R.. Studies on the 
Properties of an Unproductive Soil, U. S. Dept. Agr., Bur. Soils Bui. No. 28. 

1905. 



154 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The authors of this bulletin do not make it clear whether they con- 
sider the evidence brought forward in this connection as substantiat- 
ing the " toxic " interpretation of crop rotations, that is, whether they 
w^ould expect different results if several crops were used in a rotation 
under the same conditions. 

The results of these experiments would really tend to show that 
the depressing effects of the previous crops were not due to deple- 
tion of plant food. They do not show conclusively, however, that 
the inferior yields were due to toxic root excreta nor that the secre- 
tion of toxic substances might be a factor under natural field con- 
ditions. The experiments were conducted under such unnatural con- 
ditions that in many of them the depressing effects might have been 
due to physical deterioration of the soil. This interpretation would 
be in harmony with the fact that lime and cowpeas had a more de- 
cided ameliorating effect than fertilizers. 

It is, however, possible that in all the results here reported the de- 
pressing effects were due to conditions associated with seed germina- 
tion, since the crops in all cases were grown only for short periods. 

The phenomena of seed germination are so entirely different from 
conditions of plant growth after the plant begins to draw its nutrition 
from the surrounding medium that they ought to be considered sep- 
arately. The metabolic changes, both destructive and constructive, 
during the period of seed germination are so rapid, so many different 
enzymes are involved in the transformation of the products stored up 
in the seeds, and so much organic material is made available for the 
growing embryo that the products of seed germination may become 
harmful to plants when they accumulate, either directly or through 
the agency of micro-organisms which they may attract. 

However, the phenomena associated with the processes of seed 
germination are a natural stage in the evolution of plants. Each step 
in the development of the plant is adapted to the corresponding stages 
of the seed metabolism and its normal growth is, therefore, not inter- 
fered with by the products of germination of its mother seed under 
natural conditions. As to the effect on the succeeding crop, the 
products of metabolism in the process of seed germination are of such 
unstable nature that they can hardly be expected to last until the next 
normal crop and can hardly be a factor in soil fertility under normal 
conditions when crops are grown to maturity. 



D.wiDSON : 1':ffi:( r ov ci'mauin and vanillin on wiii:at. 155 



W'llKAl- SlKDI.lNCS (IkoVVN IN .\(i.\U.-" 

Soi^nicnls of s^lass liil)inj4' about three cent inicters loni;- and having' 
an internal diameter ol" (> to S millimeters were fastened in a vertical 
position to a i^lass rod at intervals of 2 to 3 millimeters. The seg- 
mented tubes were i)laced in small jars and molted ai^ar was ])ourcd 
in them till its level i-eaehed the surface of the upper segment. When 
the aj^ar cooled down to 35^" to 3(S° C, wdieat seedlin.^s were ])lanted 
in the up])er sci^inents of the sei^'mentcd tubes. 

About 53 percent of the seedlings i^rew out throuj^h the openings 
of the segmented tubes into the surrounding agar. When the experi- 
ments were repeated with agar in wdiich seedlings had been previously 
allowed to grow a smaller percentage of the roots curved into the seg- 
mented openings. When the same experiments w^ere carried out in 
such a way as to ehminate the geotropic tendency of the roots by the 
use of a klinostat, a greater percentage of roots curved out into the 
openings. When fresh agar was used inside of the segmented tubes 
and agar in which seedlings had previously been grown outside of 
them, the percentage of curvatures was smaller. On the other hand, 
a larger percentage of curvatures was obtained when used agar was 
placed inside of the segmented tubes and fresh agar outside of them. 
Certain relationships were obtained with reference to the behavior of 
wheat seedlings when agar in which corn, cowpeas and oats had been 
grown was used outside and inside of the segmented tubes. 

These facts tend to show, according to the authors, that the roots 
of the plants included in the experiment excrete certain substances 
deleterious to themselves, but less or not at all deleterious to other 
plants, the tendency to grow into the openings being due to the stimu- 
lus of negative chemotropism, a tendency to grow away from a 
harmful substance. 

A closer examination of the figures presented in connection with 
these experiments shows so much variation between the individual 
experiments that we are hardly justified in considering the averages 
as the expression of the general tendency of the phenomena. 

The curving into the openings might have been due to a cause of 
a physical nature, the slight tendency of the averages to behave in 
the expected direction being simply accidental. The growing tip, as 
it is generally known, exerts a considerable pressure. This perhaps 
forced the agar in the narrow segments into the openings and the 
roots were carried along with the agar, or the curving into the open- 
ings might have been due to the general spreading habits of the root 
system. 

Schreiner and Reed, 1. c, p. 23-36. 



156 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

If, however, the curving into the openings was really due to dif- 
ferences between the agar in the segmented tubes and the outside 
agar, the theory of toxic excreta is not the only possible explanation. 
The tendency to curve into the openings might have been due to 
water relations, there being more available water outside of the 
narrow segmented tube. This possibility becomes more plausible 
when we take into consideration the fact that while chemotropism in 
higher plants has not been definitely established, hydrotropism, or 
the movement toward water, is a well-known phenomenon. 

Behavior of Wheat Seedlings in Water Extracts of S01L.22 

The behavior of soil extracts is brought forward as evidence in 
favor of the existence of toxic substances in soils, regardless of 
their origin. 

It was found that a poor soil extract yields poorer crops than dis- 
tilled water. The depressing ei¥ects of the extract could not be due 
to lack of plant food, since it contains more of it than the distilled 
water. When an extract of a poor soil is diluted the yield is im- 
proved, notwithstanding the fact that the diluted extract contains 
less plant food. A case is reported in which the poor properties of a 
soil extract were transferred to its distillate, which would tend to 
indicate the presence of some volatile toxic substances. When a poor 
soil extract was used in making up a balanced solution the yields ob- 
tained were inferior to those which were obtained when the same 
balanced nutrient solution was made up with distilled water. The ad- 
dition of substances which have no nutritive value at all, as pyrogallol, 
ferric hydrate and carbon black, improves greatly the crop productiv- 
ity of the poor soil extract. The beneficial effects of these substances 
is ascribed to their power of absorbing the toxic substances present 
in the extracts. 

All these facts would tend to show that there is something in the 
extracts of the poor soils which interferes with plant growth, although 
some of these facts do not bear necessarily on the presence of toxic 
bodies. It was found, for instance, that the addition of solids, as 
carbon black, ferric hydrate, etc., improves a good soil extract also, 
although not to so great an extent as it improves a poor soil extract. 
It is possible that the action of the added soHd is absorptive, but the 
good soil extract also contains comparatively small amounts of toxic 
substances and it is, therefore, also improved by the addition of ab- 

21 Jost, L., Lectures on Plant Physiology, pp. 484-485. Oxford, 1907. 
U. S. Dept. of Agr., Bureau of Soils Bui. 28, 36, and 40. 



D.w insox: i-.i' i-i:c 'im)|- c i'm aki \ and v.\ n ii.i.i n on v\ iii:A r. 157 



sorhiui^ .li^cnts. It is, however, also ])ossil)le thai the efreet of the 
solid is due to some other eause, the action perhaps heini; on the 
])lant rather than on the nuMhnni. It is j)ossil)Ie. for instance, thai 
ihe solids stimulate a response in plant roots jusl as gravity does 
( i^eotropism). If so, the dilTerent extent of the effects of the solid 
on the poor and j^ood soil extract would he due rither to the dillci-cnt 
l)roperties of the extracts which alYect that response dilTerentlx', or 
to the limits of possihle ini])rovement. 

.\s to the effects of dilution on the productive ca])acity of the ])oor 
soil extract, the results obtained lose much of their force as a proof in 
favor of the theory of soil toxicity because it has never been tried on 
a good soil extract. It would perhaps be found that good soil ex- 
tracts would also be improved by dilution and it would then be pos- 
sible to suggest some other explanation of the beneficial effect of dilu- 
tion in addition to the one based on the dilution of the toxic substances. 

The yields in the experiments with soil extracts were generally 
measured by transpiration, which is not always a reliable indicator of 
plant growth. The plants were grown only for periods of two to 
three weeks, under which condition too much significance can not be 
attached to differences in yield if they are not striking, as was the 
case in many of these experiments. 

The results obtained with soil extracts in general could hardly be 
considered as due to the same factors which are operative in the poor 
soils from which they were prepared under field conditions. This 
is because the extracts were prepared in such a different manner for 
the natural soil solution (excess of solvent, shaking, etc.), and since 
the soil, as it was shown, has such an ameliorating influence on the 
poor properties of a liquid medium, even when present in very small 
quantities.-^ 

Isolation of Toxic Substances from Soils. 

A number of organic compounds have been isolated by Schreiner 
and Shorey-^ from different soils and some of them have proved to 
be toxic to plants in water cultures, as picoline carboxylic acid and 
dihydroxystearic acid. With reference to picoline carboxylic acid, 
the authors have admitted that it was hardly a factor in soil fertil- 
ity.-^ They think, however, that dihydroxystearic acid is directly re- 
sponsible for the poor yields of the poor soils from which it has been 
isolated, since it shows depressing effects in water cultures even when 

23 Livingston, B. E., et al., 1. c, p. 35. 

24 Schreiner, Oswald, and Shorey, Edmund C, The Isolation of Harmful 
Organic Substances from Soils, U. S. Dept. Agr., Bur. Soils Bui. No. 53, 1909. 

25 L. c, p. 47. 



158 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

present in concentrations as low as 20 parts per million. It is ques- 
tionable, however, as previously pointed out, whether conclusions 
with reference to actual field conditions can be drawn from results 
obtained in water cultures. 

Dihydroxystearic acid has been isolated from good soils as well as 
from poor soils, although much more frequently from the latter than 
from the former. It has been admitted by Schreiner^^ that di- 
hydroxystearic acid is perhaps not responsible for the low productive 
capacity of the poor soils from which it has been isolated and that 
it is possible that its presence is a result of the same conditions which 
render the soils poor. Furthermore, the very presence of dihydroxy- 
stearic acid in soils from which it has been isolated is not definitely 
established as it is possible that it is formed during the process of 
extraction. 

Summary. 

It IS apparent from the foregoing analysis that the evidence which 
is offered in favor of the theory of soil toxicity is neither direct nor 
conclusive. The facts on which it is based can be interpreted in a 
variety of ways other than the existence of toxic substances. 

The question would be considered definitely settled if toxic sub- 
stances isolated from a poor soil, when applied in the same quantity 
in which they are there present, caused a soil which does not contain 
them to produce a poor crop similar to that produced by the poor soil. 

Indirect or circumstantial evidence is of less value in problems of 
soil fertility than in many other problems. So many factors known 
and unknown affect the soil that several interpretations of the same 
phenomena are frequently possible. The real significance of these 
phenomena may often escape us because of our lack of knowledge of 
the processes taking place in the soil. 

(To be concluded in the Septemher-Octoher Journal.) 

2« Schreiner, O., and Lathrop, E. C, Dihydroxystearic Acid in Good and Poor 
Soils, Jour. Amer. Chem. Soc, 33 (1911), P- 1412-1417. 



I 



LAi v : si:ki) \ aiaiks oi- m aizi-: ki;unkls. 159 

SEED VALUES OF MAIZE KERNELS, BUTTS, MIDDLES AND 

TIPS.' 

Mary (i. T.acy, 

Bureau of Plant Txhiistry, U. S. Dkpartmknt of Acriculturr. 

Introduction. 

Afany efforts have been made to determine the relative value as 
seed of the kernels from the different parts of the ear of Indian corn, 
but the results have appeared so contradictory that little progress has 
been made toward any definite concltisions. Generally speaking, the 
directions given have been to throw away the butts and tips of the 
ear and to plant only seed from the middle portion. A variety of 
reasons have been advanced for this practice. 

In connection with the preparation of a bibliography and index of 
the literature relating to maize, there has been an opportunity to re- 
view the work which has been done along this line. This canvass 
of the subject was undertaken at the suggestion of Mr. G. N. Collins, 
who considered it worth while to determine how far the apparently 
contradictory results of the different experiments could be recon- 
ciled by taking into account the fact that the silks of the kernels from 
the tip end of the ear are the last to appear. They often are not e-xserted 
until all the pollen from the plant has been shed, hence the tip kernels 
are more likely than the others to escape self-fertilization, with the 
accompanying decrease in vigor and productiveness. During the ex- 
amination of the literature it was learned that Hunt (1909)- had sug- 
gested the same explanation, but he seems to have made no attempt 
to determine whether the experimental data would support this inter- 
pretation. 

In this paper all of the data that have been given by the different 
experimenters are brought together, arranged for comparison, and 
reviewed, to see whether any definite differences have been shown, 
and if so, whether these could be ascribed reasonably to the greater 
chances of cross-fertilization of the kernels at the ends of the ear. 

1 Received for publication February 25, 1915. 

2 Dates in parentheses refer to the bibliography at the end of the paper. 



l6o JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Early Opinions on the Use of Tip Seed. 

For more than a century and a quarter directions have been given 
as to what part of the ear of corn should be used for seed. Parmen- 
tier (1785), Harasti (1793), Des Michels (1829) and Bonafous 
(1836) all warn against the use of kernels from the tip of the ear for 
seed, as they state such kernels are not so " well nourished " as the 
others and are likely to produce weak plants. However, when Des 
Michels adds to the above statement, as an additional reason for not 
planting tip kernels, because often they have not been fertilized," 
we begin to suspect that he was not reporting the results of experi- 
ments or accurate observation. It was probably common practice 
then as now to use the kernels with the best appearance for seed, 
and these are undoubtedly found on the middle of the ear if uniform- 
ity of size and shape is the criterion. Modern practices of careful 
selection and testing of seed ma*ke it desirable to use all of the seed 
from the best ears. Certainly none of the best seed should be dis- 
carded unless there is a practical reason for doing so. 

Popular Objections to the Use of Tip Seed. 

The introduction of modern corn-planting machinery strengthened 
the practice of discarding the tips for seed. When using a corn 
planter, a uniform stand can only be obtained with seed of approxi- 
mately the same size and shape, so that the small tip and distorted 
butt kernels seem undesirable. It has thus become the practice in 
many sections to discard the butts and tips of the ear and to use only 
the kernels from the middle of the ear for planting. A great deal 
has been written about the loss occasioned by an irregular stand, but 
an experiment carried out in Nebraska by Montgomery (1909) shows 
that this loss has been overestimated. The data gathered by Mont- 
gomery show that ordinary variation in rate of dropping will have 
little or no effect on the yield per acre, as the plants contiguous to 
any unused space profit materially by the increased nutriment at their 
disposal. So we must look further for a reason for discarding the 
butts and tips of the ears. 

The next objection urged against the use of tip seed is that the 
strongest plants come from the largest and heaviest seeds and the 
smallness of tip kernels makes them undesirable for planting. 
Georgeson, Burtis and Shelton (1891) report an experiment planned 
to settle the question whether a corn plant grown from a small kernel 
is just as thrifty and will yield as well as one grown from a large 
seed. Ten twentieth-acre plats were devoted to this experiment, 



LACV : si;i'.i» N Ai.ri'.s oi' m.\i/i, ki:kM';i.s. i6i 

which was coiuliuicd willi iho St. ( h.irk's (U-iil corn. The results 
I)lainly show that there is praclicall)' no (hllcrcnci- in ihc rcsuUin.i,^ 
plant whether the seed kernels are lar^e or small, jjrovidcfl they arc 
sound. Sturte\ant (iSS:^) says: 

" Small kernels selected for their diniituitive si/.e from a normal car, yield 
plants and crops not only e(iual but curiously enough often sui)erior to those 
grown from kernels of normal si/.e. hi one case where very small shrivelled 
kernels of Waushakum corn were collected from a tassel where abnormally 
borne, and used for seed, the crop was very superior in quality and yield and 
every ear perfect in type. Sixteen seed yielded eighteen good ears from six 
to nine inches long, and four unmerchantable ears. So far as our observations 
at present extend, the small size of the tip kernels offers no objection for cer- 
tainty of growth or yield but the hybridization from plants from large seed 
may possibly vitiate our trial." 

Sturtevaut (1885) later carried out an experiment in regard to the 
elTect of the size of the seed on the resulting plant. The figures ob- 
tained (Table i) show very little difference between the crops from 
the two kinds of seed. 



Table i. Relative Yield from Large and Small Seed (after Sturtevaut) . 





Number of 
Good Plars. 


Number of 
Poor Ears. 


Bushels of 
Good Ears. 


Bushels of 
Poor Ea rs. 


Average Weight 
of Ears. 












Ounces. 


Large seed 


14.360 


1,630 


69.7 


2.1 


6.21 


Small seed 


14.390 


I.9S0 


67.9 


2.1 


6.04 



First Recorded Experiments on the Subject. 

In 1857 we have the first report of a series of experiments as to 
the best part of the ear to plant. These experiments were carried 
on for ten successive years to find out the relative merits of butt, tip 
and middle kernels for seed. Flint (1857) says: 

" A farmer planted only the corn from the small end of the ears, choosing 
such as were well filled out ; then only from the middle of the ears ; then only 
from the big ends. After ten years he found that in seven years of the ten the 
crop from the small end was the largest and the best." 

Tw^o years later Flint (1859) says: 

" In selecting corn for seed the tips of the ears are thought to be best, and 
that part near the butt end of the ear next in value. . . . The experiment of 
planting seed taken from different parts of the ear has been repeatedly tried, 
and the result has almost uniformly been better from that taken near the tips, 
however contrary it may be to the theories received, in regard to tke full and 
complete development and perfection of seed." 



1 62 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



The first experiments to determine the relative merits of butt, 
middle and tip seed which were carefully planned and fully reported 
were those of E. L. Sturtevant of the New York Agricultural Ex- 
periment Station. Of these experiments Hall (1907) says: 

" Probably few experiments in field crops ever excited more comment than 
those carried on at the station in 1882, '83, '84, and '85, by which it was estab- 
lished that there is practically no difference in germinative ability or crop- 
producing power between seed from the tip, middle or butt of the ear. The 
criticisms of this work ranged all the way from dogmatic assertions that the 
experiment was idiotic throughout, in conception, execution and conclusion, to 
unqualified praise of the station for demonstrating scientifically a fact that 
might be of great practical value to the growers of corn." 

Experimental Data. 

Since the experiments recorded by Flint no less than 16 sets of ex- 
periments have been made to determine this question, including those 
of Sturtevant just mentioned. Of these 10 have been reported in 
such a way as to make tabulation and comparison possible. Table 2 
is the result of the tabulation. It will be seen that in every case the 
yield of seed taken from the middle of the ear has been represented 
by icq and the relative value of the yield from the butt and tip as 
compard with that of the yield from the middle has been computed. 
In other words, the yield of butt and tip seed is expressed as a per- 
centage of the yield of the middle seed. In the 81 different trials 
the yield from the butt seed averages 3 percent and that from the tip 
seed 5 percent greater than from the middle seed. 

In addition to the 81 experiments so reported as to be comparable, 
North Carolina, Minnesota and Michigan have done some work along 
this line, but have not given particulars. Pennsylvania has done 
much more than Table 2 indicates, but a large part of the work was 
reported with insufficient data. In that state the experiments were 
carried on for eleven years but for four only were the results re- 
ported fully enough to enable a comparison with the results secured 
by others. 

Definition of Butt and Tip Seed. 

In considering Table 2, the question arises as to what is considered 
tip, and what butt seed. In one-half the experiments which were 
tabulated, it is stated what part of the ear was considered as butt or ^ 
tip. These data are given in Table 3. 

From Table 3 it is seen that Alabama, Arkansas, Kansas and New 
York took the extreme ends of the ear as tip and butt seed. Georgia 

i 



lacy: SKicn valuks of maizi-. ki km i s. 



16 



r \ni.K J. SiDtininry of n.vf^crimriits on RclatiTi' Yield of Srcd from Butt, 
Middle and Tif> of Maicr liars. 



Year, j 


Hiitt. 


Mill- 
tile. 


Til) 


1 896 


114 


100 


97 


I 


99 


100 


97 


I oQO 


151 


100 


131 


1896 


101 


100 


90 


1897 


lOI 


100 


112 


1898 


94 


100 


103 


1892 


III 


100 


99 


1896 


102 


100 


104 


1900 


100 


100 


104 


I9IO 


1 07 


100 


III 


lOI I 


III 


100 


III 


I89I 


102 


100 


84 


I89I 


102 


100 


99 


I89I 


127 


100 


131 


I89I 


105 


100 


91 


I89I 


98 


100 


94 


1892 


87 


100 


98 


1893 


142 


100 


109 


180^ 


118 


100 


116 


1893 


155 


100 


159 


1893 


84 


1 00 


221 


1893 


100 


100 


75 


1895 


112 


100 


96 


1896 


00 

yy 


100 


89 


1896 


107 


100 


lOI 


1896 




100 


106 


1886 


120 


100 


III 


1888 


99 


100 


95 


1889 


100 


100 


lOI 


1890 


117 


100 


114 


1891 


99 


100 


95 


1892 


96 


100 


103 


1893 


96 


100 


98 


1894 


99 


100 


106 


1895 


98 


100 


lOI 


1896 


94 


100 


85 


1896 


104 


100 


102 


1869 


97 


100 


98 


1870 


98 


100 


97 


1871 


84 


100 


103 


1872 


III 


100 


109 


1869 


72 


100 


81 


1 /U 






130 


I87I 


109 


100 


III 


1872 


78 


100 


78 


1882 


134 


100 


134 


1883 


99 


100 


104 


1883 


96 


100 


104 


1883 


104 


100 


99 


1883 


99 


100 


100 


1883 


97 


100 


115 



\aritty. 



Size of 
Plot. 



No. of 
Plots. 



Yellow 



lint Expt. Sta 
Dent Rentro 
Do 

Hickory King 
Expt. Sta. Yellow 
Do. 



Do. 
Flint 
Do. 



Dent iWhite Dent 



Dent 
Do. 



Dent 
Do. 
Do. 
Do. 
Do. 



Dent 
Do. 
Do. 
Do. 
Do. 
Do. 



Dent 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 



Barnes' Mammoth 
Marlborough 



St. Charles 
Do. 
Do. 
Do. 
Do. 



Dole 90-Day 
Do. 
Do. 
Do. 
Do. 
Do. 



Flint 
Do. 
Do. 
Do. 
Do. 
Do. 



Waushakum 
Do. 
Do. 
Do. 
Do. 
Do. 



(Acre) 
1/9 , 
1/9 I 
1/9 
1/9 
1/8 



1/20 
1/20 
1/20 
1/20 
1/20 



i/io 
i/io 
i/io 



1/8 
1/8 

1/8 
1/8 
1/8 
1/8 
1/8 
1/8 




2 
6 
17 
17 

I 

r 
I 
I 
I 

5. 
I 
I 
I 
I 
I 

5 
I 
I 
I 

I 

a 
I 
2 
4 

3- 
3 
3 

2- 
2 



164 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Locality. 


Year. 


Butt. 


Mid- 
dle. 


Tip.. 


Type. 


Variety. 


Size of 
Plot. 


No. of 
Plots. 


New York. . . 


1883 


104 




100 


102 


Do. 


Do. 


1/20 


I 




1883 


98 


100 


99 


Do. 


Do. 


1/20 


I 




1883 


93 


100 


105 


Do. 


Do. 


1/20 


I 




1883 


102 


100 


103 


Do. 


Do. 


1/20 


I 




1883 


109 


100 


lOI 


Do. 


Do. 


1/20 


I 




1884 


95 


100 


98 


Do. 


Do. 


1/20 


I 




1884 


107 


100 


109 


Do. 


Do. 


1/20 


I 




1884 


116 


100 


115 


Do. 


Do. 


1/20 


I 




1884 


95 


100 


106 


Do. 


Do. 


1/20 


I 




1884 


99 


100 


103 


Do. 


Do. 


1/20 


I 




1884 


92 


100 


108 


Do. 


Do. 


1/20 


I 




1884 


95 


100 


84 


Do. 


Do. 


1/20 


I 




1884 


93 


100 


104 


Do. 


Do. 


1/20 


I 




1884 


107 


100 


120 


Do. 


Do. 


1/20 


I 




1884 


91 


100 


106 


Do. 


Do. 


1/20 


I 




1884 


105 . 


100 


107 


Do. 


Do. 


1/20 


I 




1884 


lOI 


100 


103 


Do. 


Do. 


1/20 


I 




1884 


lOI 


100 


93 


Do. 


Do. 


1/20 


I 




1884 


91 


100 


108 


Do. 


Do. 


1/20 






1884 


06 


100 




Do. 


Do. 








1884 


99 


100 


98 


Do. 


Do. 


I /20 






1884 


96 


100 


lOI 


Do. 


Do. 


1/20 






1884 


100 


100. 


102 


Do. 


Do. 


1/20 






1884 


93 


100 


98 


Do. 


Do. 


1/20 


I 




1884 


95 


100 


100 


Do. 


Do. 








t88"; 






yo 


Do. 


Do. 


i/To 




Tennessee . 


190 I 


T 9 7 


100 


yo 










Wisconsin . . . 


I87I 


104 


100 


95 


Do. 


New England 








1873 


94 


100 


96 


Do. 


Do. 








1874 


102 


100 


113 


Do. 


Do. 






Means 




103 ±.9 


100 


ios±i 











shelled off one inch from end of tip -and discarded these kernels, 
then planted ^ of the remainder. As New York planted the 5 tip 



Table 3. Part of Ear Considered as Tip and Butt in the Various Experiments. 



Locality. 



Alabama 

Arkansas 
Georgia 
1896 

1900 
1910 
1911 
Kansas 

New York 



Tip. 



First inch of tip. Only 

sound kernels used. 
First of ear. 
I inch from end of tip 

shelled off and discarded. 

Next 2 inches planted. 
I inch from end of tip 

shelled off and discarded, 

Ys of remainder planted. 
Extreme end of ear. Only 

sound kernels planted. 
5 tip grains [rows] 



First inch of butt. 

Last Vo of ear. 
2 inches of butt. 



Last Vs planted. 

Extreme end of butt. Only 

sound kernels planted. 
.M butt grains [rows] 



LA(^V : Sl'.KH VALUl'S Ol' MAI/J-. K h.U N i:i.S. 



and the 5 bull rows il w ill he seen thai ( icorj^ia (Hscardi'cl all that 
jKirt of tlio car corrospoiulin.i^ to the part which New N'ork planlcfl, 
and ihc results arc seareel\' eoinparahle. l-'or hull seed ( ieorgia 
planted the last of the ear, hein*;- j/j of the total length and inelud- 
ini^" nuieh more of the seed near the middle than any of the other ex- 
])erimenls. In spile of these facts, in the ( ieorj^ia e.\j)erinienls the 
yield from the ti^) seed was hij^her than that from either the butt or 
the middle seed in 3 out of 4 cases, and in the fourth case was e(|ual 
to the yield of the butt seed, which was 11 ])ercent ^^^reater than the 
yield from the middle seed. It is much to be regretted that Ohio, 
Ontario, Pennsylvania, Tennessee and Wisconsin (hd not indicate 
exactly wdiat part of the ear w^as used as tip seed and wdiat part as 
butt seed. 

Discussion of the Experimental Data. 

It is interesting to note that in the 81 trials reported in Table 2, 
the yield of butt seed ranges from 28 below the middle to 55 above, 
and the range of the yield from the tips is even larger, being from 25 
below^ to 121 above the middles. Are these wide differences acci- 
dental, or are there conditions or varieties where dififerences of similar 
magnitude may be expected as a more or less regular occurrence ? 

The Kansas experiments with Dole 90-Day corn give both the 
highest and the lowest yields for tip seed and the highest yield re- 
corded for butt seed and the next to the lowest. Is Dole 90-Day corn 
a variety which fluctuates very much as to yield? Or is the Kansas 
climate w^ith its wide range of temperature responsible for such 
variation ? 

It w^ould seem that the figures in Table 2 and the observations of 
the various writers quoted are conclusive in showing that no one part 
of the ear is markedly inferior for seed. The kernels from both the 
tip and the butt appear more prolific than those from the middle of 
the ear, and the tip seed is better than the butt. 

Atkinson (1901) says that many farmers plant the seed from the 
entire ear, as the plants from the tip and butt kernels do not bloom 
at the same time as those from the middle kernels, and by this means 
the period of pollination is prolonged, thereby insuring a more com- 
plete fertilization of the ovules. Atkinson, however, gives no indica- 
tion that definite data had been collected to support this opinion. 

Speer (1888) says that the silks from the tips of the ears are gen- 
erally from two to five days later than those from the lower part of 
the ear, and in some cases have been observed to be as much as ten 



1 66 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

days later. Speer also notes the fact that the silks last fertihzed 
produce the smallest kernels. 

Halsted (1912) thinks that the first silks to appear are from a 
midzone of the ear, from which point development proceeds both 
towards the tip and the butt. Gernert (1912) says: 

" The statement by some writers that the silks from the base of the ear 
appear first, is true only in a broad sense, meaning the lower portion of the 
ear. Many poorly filled butts and bare tips are found on ears polienated soon 
after the first silks appear." 

He gives an illustration of an ear of pearl popcorn pollinated at 
two different stages in its development, of which he says : 

" The variety to which the ear belongs is a white pop and in the forenoon of 
the day on which the first silks appeared on this shoot it was selfed. Eight 
days later the silks were observed to be long and green, and pollen from a 
plant in a variety with a yellowish endosperm was then applied. The phenom- 
enon known as xenia brought out the difference between the selfed and the 
hybrid kernels, as is apparent in the figure. It is significant that the first silks 
to appear did not come from the extreme base of the ear but slightly above.it 
(as is shown by the irregular band of white kernels). At the end of eight days 
the silks at the tip of this ear were not yet developed as is indicated by the bare 
cob at the tip of the ear in the figure." 

Gernert adds, however, that the appearance of the silks from the 
cob is very non-uniform. Perfect ears have been obtained in some 
instances by pollination on the second day after the silks were visible, 
although in the case just quoted the silks from the tip of the ear had 
not emerged at the end of eight days. The order of the appearance 
of the silks seems to vary greatly with different varieties of corn. 

If there is an absence of wind at flowering time, there is little 
doubt that the silks from the butts and tips would be oftener cross- 
poUinated than those from the middle of the ear, and hence yield 
more. If this is the true explanation there should be many instances 
when there is little or no difference in the yield from the middle and 
end seed, but there should also be instances when the end seed gives 
larger yields. The figures in Table 2 support the view that in cases 
where winds at pollination time insure cross-pollination for the silks 
from the middle of the ear, there would be no difference between the 
yield from the butts, tips and middles that could not be accounted 
for by chance, while on the other hand, when atmospheric conditions 
are good for self-pollination, the yields from the tips and butts would 
be greater than from the self-pollinated middle seed. In other words, 
the large deviations should be in favor of the end seed. Further, 
when the tip yields are significantly greater than those from the 



LACV : si:i:i) \ \i.i'i:s oi' maizi'. Ki.uxia.s. 



167 



middle seed, llio hull yields should also he i^rcali-i-. whereas when tip 
yields are low (the tahle shows them never lo he lower than ean he 
aeeounted for h)' ehauee ) the hutl yic^lds may or may not he eorre- 
spoiidiniily low. The lij^ures do show jusl this. 

T.et us examine them with this in mind. The ])rol)al)le eri-or for 
the indi\idual exi)erimenl taken without regard to size of ])lot, is it 
S.S for tips and zb 7.9 for hutts. Jf we take a deviation from the 
yield of middle seed of at least four times the ])rohal)lc error as too 
g^reat to he attrihuted to ehauee, we find in Tahle 2, that there are 
for the tips 3 such deviations ahovc the mean, and for the hutts, 4. 
In 3 of the 4 cases where the yield of the hutts exceeds that of the 
middles by a signiiicant amount the yield of the tips is also high. 
There is no deviation below the middles as large as four times the 
probable error, the lowest figures being 28 for butts and 25 for tips. 
Relative yield of tip and butt seed may also be influenced by the 
type of corn used, whether flint or dent. 

Comparison of Flint and Dent Corn. 

Table 4 is a rearrangement of the data exhibited in Table 2, and 
is designed to show the comparative behavior of flint and dent corn, 
regarding the relative yield from butt, middle and tip seed. It will 
be seen that with dent corn the yield of tip and butt seed respectively 
is 8 and 9 percent above the yield from seed from the middle of the 
ear. whereas with flint corn the yield from the butt seed is equal to 
that from the middles and the yield from the tip seed 4 percent 
greater than from the middles. Flint corn has been reported to show 
pollen and silk at the same time much oftener than dent corn does 
(Sturtevant 1883). Experiments may show further that the dis- 
parity in the time of appearance of silks from the middle and the 
ends of the ear is also a character that differentiates the flint from 
the dent varieties. It should also be kept in mind that the greater 
tendency of flint varieties to produce tillers extends the period dur- 
ing which pollen is being shed and reduces the chances of differential 
pollination. This table seems to support the observation made by 
Duggar (1896) and Georgeson, Burtis and Shelton (1891) that dent 
varieties yield most from butt seed whereas flint yields most from 
tip seed. 

Germination. 

The relative germination of butt, middle and tip seed was noted by 
Sturtevant (1883) in connection with his experiments as to relative 
yield. His data are given in Table 5. 



1 68 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 4. Flint and Dent Corn Compared as to Relative Yield of Butt, Middle 

and Tip Seed. 



Flint Corn. 


Dent Corn. 






Relative Yields. 






Relative Yield. 


Locality. 


Year. 




ivxiu- 




Locality. 


Year. 












Butt. 


die. 


Tip. 






Butt. 


Middle. 


Tip. 




1896 


114 


100 


97 


x^XctUdXllcl . 


1 896 


99 


100 


97 




t8o'7 
X oy / 


lOI 


100 


112 




1896 


151 


100 


131 




1898 


94 


100 


103 




X 090 


lOI 


100 


90 


iNCW JL UX Jv . . 


1882 


134 


100 


134 


A 1 

ArKa.nsa.s . 


T 8m 

X oy^ 


III 


100 


99 




1887 

X 00 J 


99 


100 


104 


\J\ZUI ^Xd . . 


1900 


100 


100 


104 






96 


100 


104 




I9IO 


107 


100 


III 




X OOJ 


104 


100 


99 


J\.a,ns3.s. . . 


X 09 i 


102 


100 


84 




188^ 
X 00^ 


99 


100 


100 




I89I 


102 


100 


99 






97 


100 


115 




I89I 


127 


100 


131 




188^ 

X 00^ 


104 


100 


102 




I89I 


105 


100 


91 




1883 


98 


100 


99 




I89I 


98 


100 


94 




t88^ 
X 00^ 


93 


100 


105 




T Rni 


142 


100 


109 




X 00^ 


102 


100 


103 






118 


. 100 


116 




X 00 j 


109 


100 


lOI 




T 8m 


155 


100 


159 




1884 


95 


100 


98 




T 8n-2 


84 


100 


221 




1884 


107 


100 


109 




T Sm 


100 


100 


75 




1884 


116 


100 


115 




T Rr> c 

J^o95 


112 


100 


96 




1884 


95 


100 


106 


Ohio 


1886 


120 


100 


III 




1884 


99 


100 


103 




1888 


99 


100 


95 




1884 


92 


100 


108 




1889 


100 


100 


lOl 




1884 


95 


100 


84 




I 890 


117 


100 


114 




1884 


93 


100 


104 




I89I 


99 


100 


95 




1884 


107 


100 


120 




T 8m 

X oyz 


96 


100 


103 




1884 


91 


100 


106 




T 8n-> 

i»93 


96 


100 


98 




1884 


105 


100 


107 




T Sn A 

i»94 


99 


100 


106 




1884 


lOI 


100 


103 






98 


100 


lOI 




1884 


lOI 


100 


93 




1896 


94 


100 


8 c 
05 






91 




108 














1884 


100 
















1884 


96 


100 


95 






I09±2.04 


100 


io8±2.8i 




1884 


99 


100 


98 








1884 


96 


100 


lOI 














1884 


100 


100 


102 














1884 


93 


100 


98 














1884 


95 


100 


100 














1885 


95 


100 


98 












Wisconsin. . 


1871 


104 


100 


95 














1873 


94 


100 


96 














1874 


102 


100 


113 












Means 




ioo±.8o 


100 


i04±.84 



























Table 5. Relative Germination of Butt, Middle and Tip Kernels. 



Type. 


Variety. 


Butt. 


Middle. 


Tip. 


Flint. 




IIO 

98 
342 
100 


100 
100 
100 
100 


132 

100 

138 

97 


Dent. 




Do 


Early 


Do 


Sibley's Pride of the North . 






142 ±25 


100 


II2±5 







T.ACV : si:i':i) \ \i.ri:s oi" m k i;u n i:i s. 169 

These exi)eriments. alllioiimh (00 frw lo have iiuuli uci^hl, arc 
interesting heeanse of their j^eneral ai^n-enient with TahK' J. I )evol 
(1883) earries out some similar experiments and reports the resuUs, 
hilt not in sueh a way as to enahle us lo tahulate tliem. I le says that 
in 96 tests of the rehitive ^germination of the l)Utt, tij) and middle 
seed of eorn, 70.3 pereent of the tij) seed germinated, 5S.7 ])ereent 
of the middle seed, and 76.3 ])ereent of the hutt seed. The following 
year there were 580 tests made, in whieh 76.1 percent of the tip seed, 
74.2 pereent of the middle seed, and 84 percent of the hutt seed |[^er- 
minated. He j^oes on to state, hut without any data to sui)port the 
observation, that the radicle from the ti]) kernels is almost invariably 
weaker than from the butt or middle kernels. The root from the 
middle kernels sends out its root hairs sooner than the root of the 
butt kernels does. The butt kernels send out two lateral rootlets 
nearly as strong as the central root and almost simultaneously w^ith 
it, while the lateral roots are weaker in the middle kernels and slower 
to start. 

Sturtevant (1883) thinks that probably germinative and vegetative 
properties do not always correspond. The vitality of tip kernels is 
shown to be manifestly superior to that of the butt or middle kernels 
in flint corn, by the higher percentage of germination ; the tip kernels 
of dent corn, however, did not show this superiority. Flint corn 
dries out more quickly than dent, which may account for its greater 
germinative ability. It has been suggested by the Ohio Agricultural 
Experiment Station in Newspaper Bulletin 170, 1897, that as the ends 
of the ear dry out more quickly than the middle portion, it may be 
that under some conditions the middle grains may be injured w^hen 
the butts and tips escape. 

Conclusions. 

It w^ould seem, if practical results are what is sought, that the ex- 
periments reported, covering a period of 45 years, are sufficient to 
decide the relative merits of butt, tip and middle kernels for seed. 
The experiments have been planned carefully, have been carried out 
in the various climates suited to corn growing, and ten different varie- 
ties of corn have been used. 

The figures in Table 2 give the average yield of seed from the butt 
as 103 percent of that from the middle seed and the yield of seed 
from the tips as 105 percent of that from seed from the middle of the 
ear. In the case of the tips this is 5 times the probable error for the 
series, and in the case of the butts, 3^ times. These percentages, 
though small, must be considered significant in a table of 81 instances. 



170 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



The higher figure for tips over butts may be explained by the fact 
that whereas occasionally the butt and middle silks appear almost 
simultaneously, the tip silks always appear last, and so are cross- 
fertilized more frequently than those from the butt of the ear. The 
yield from tip seed, therefore, often would be greater than that from 
the butt seed, in spite of the smaller size of the tip kernels. 

In 4 out of the 81 cases reported we may be sure that the yield has 
been increased by the use of tip seed, and in the other cases there is 
no evidence that the use of tip seed has decreased the yield. In 4 
cases the increased yield from butt seed is more than 4 times the prob- 
able error. 

The conclusion of the matter seems to be that the tips and butts 
are certainly not inferior for seed purposes, and there seems little 
justification for the practice, prevalent in some sections, of discarding 
them for seed. 

Literature Cited. 

Atkinson, James. 

1901. Field Experiments. Iowa Agr. Expt. Sta. Bui. 55, p. 369-371. 
Bonafous, Matthieu. 

1836. Histoire Naturelle, Agricole et ficonomiqtie du Mais. Paris. 
Collins, G. N. and Kempton, J. H. 

1913. Effects of Cross-Pollination on the Size of Seed in Maize. U. S. 
Dept. Agr., Bur. Plant Indus. Cir. 124, p. 9-15. 
Des Michels. 

1829. Instruction sur la Culture du Mais, etc. In Soc. Cent. d'Hort. de 
France. Annales, 4: 142. 
Devol. W. S. 

1883. Seed Tests. Ohio Agr. Expt. Sta. Rept., p. 149-181. 
Duggar, J. F. 

1896. Experiments with Corn. Alabama Agr. Exp. Sta. Bui. 75. 
East, E. M. and Hayes, H. K. 

191 1. Inheritance in Maize. Connecticut Agr. Expt. Sta. Bui. 167, p. 117. 
Emerson, R. A. and East, E. M. 

1913. The Inheritance of Quantitative Characters in Maize. Nebraska 
Agr. Expt. Sta. Research Bui. 2. 

1897. Experiments with Corn. Ohio Agr. Expt. Sta. Newspaper (Press) 

Bui. 170. 

Flint, C. L. 

1857. Abstract of Returns of the Agricultural Societies of Massachusetts, 
p. 150. In Mass. State Board'of Agr. Rept. 1857. 

Flint, C. L. 

1859. Grasses and Forage Plants, p. 179-181. Boston. 
Georgeson, C. C, Burtis, F. C, and Sheltpn, Wm. 

1891. Experiments with Corn. Kansas Agr. Expt. Sta. Bui. 30, 187-188. 
Gernert, W. B. 

1912. Methods in the Artificial Pollenation of Corn. In Amer. Breeders' 

Assoc. Rept., vol. yS, p. 253-367- 



lacy: SKKi) vALUics OF MAizi': ki;i<m:i,s. 



Hall. I'. 11. 

WOrk w ith I'ii ld C iups Siimtiiai i/.i'd. New York A^r. I'-xpt. Sla. 
\<v\)[., p. 
Halstcad, 15. 1 ). 

Ixi'porl of the Rotaiiical Drpaiinu'iil, New jersey P'xpl. Sla. 

Kept., p. 272-273. 
Harasti. Gaetano. 

171)3. In.struzionc Practica Sopra la C'oltiva/.ioiie del Sor^o Turco. Ven- 
czia. p. V. 

Hunt, T. F. 

K^ci). The Cereals in America, New York. p. 200. 
Montgomery, E. G. 

igog. Experiments with Corn. Ne])raska Agr. I£xpt. Sta. l>ul. 112, !>. 35-36. 
Parmentier. A. A. 

1785. Memoire . . . siir cette question: Quel seroit le meilleur j^rocedc 
pour conscrver, le plus longtemps possible, ou en grain ou en farine, 
le mais ou hie de Turquie . . . Bordeaux. 
Roberts, H. F. 

1912. First Generation Hybrids American x Chinese Corn. In Amcr. 
Breeders' Assoc. Rept., vol. 7-8, p. 367-384. 
Speer, R. P. 

1888. Corn Tassels, Silks and Blades. Iowa Agr. Expt. Sta. Bui. 2, p. i-io. 
Sturtevant, E. L. 

1882. New York Agr. Expt. Sta. Rept., p. 40-41, 46-49. 

1883. New York Agr. Expt. Sta. Rept., p. 37, 57, 63-64, 130-132. 

1884. New York Agr. Expt. Sta. Rept., p. 90-93. 

1885. New York Agr. Expt. Sta. Rept., p. 48-50, 54-55. 



1/2 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



THE EFFECT OF DIFFERENT METHODS OF INOCULATION 
ON THE YIELD AND PROTEIN CONTENT OF ALFALFA 
AND SWEET CLOVER/ 

A. C. /\rny AND R. W. Thatcher, 

Minnesota Experiment Station, St. Paul, Minn. 

Introduction. 

The farm crops section of the Division of Agronomy and Farm 
Management of the Minnesota station has had in operation for a 
number of years a series of investigations of different methods of 
seeding alfalfa, with a view to ascertaining the best methods of secur- 
ing a uniform stand of hardy strains adapted to Minnesota condi- 
tions. Among the problems which are being studied are: The date 
of seeding; the method of seeding; the use or omission of a nurse 
crop; various methods of inoculation, with and without liming; the 
use of different forms of lime ; and tests of different strains of hardy 
varieties. Interspersed among the alfalfa plots are a considerable 
number of plots of white sweet clover which receive similar treatment. 

In the several different series of these investigations, located in 
different fields and started in different years, there are dupHcate plots 
which have received the same inoculation treatments at the time of 
seeding, with adjacent untreated check plots. Therefore, it appeared 
that these plots would afford excellent material for a comparative 
study of the effect of the different methods of inoculation, not only 
upon the yield of hay but also upon the chemical composition of the 
resultant crops. During the harvesting of the several cuttings from 
these plots in 1914, samples were taken for analysis. The results of 
the work show such consistent effects of the inoculation in the several 
different fields, at the different intervals after the year of seeding, 
that it is deemed desirable to publish them at the present time. 

The study is to be continued. The data are presented as a report 
of progress, the results seeming to justify immediate publication. 
Since this is only a preliminary report for the purpose of presenting 
data for the interest and value which they may possess, and not a 

^ Received for publication April 12, igi5. 



AU.W AND 'I'll Al( II IK : I N ( )( ' I ' I . AIM )N Ol- A I .I' A I .I' A . 



final rcxii'w of llu> iincsli.i^ation, no atlcnipt is made al lliis time {o 
review the literalme on llie snbjiH'l. 

1. TiiK 1Cffi-:ct of J^iffkrknt Mictiiods oi- Inoculation on tmi; 
YiKi^D ANH CoMrosiTioN ()!• 'nil'. Way Cuow 

I'irst Srrics, J'iclds li ami I' ; C 'oniiiiercial Culture z'crsus Inocula- 
tion re//// Soil, with and witliout Liming. — The scedings in V\M Ji 
on the l^iiversity Farm were made during the spring and summer of 
191 2. The series on which the alfalfa was sown had been heavily 
manured and cropped to mangels in 1910 and 191 1. At the time the 
alfalfa was seeded, the soil on these plots was above the average in 
productivity, because of the heavy manuring which it had received. 
Further, just across a 16-foot roadway from these plots, there was 
a series in which alfalfa had been growing thriftily for six years. 
The 19 plots of this series (1/20 acre each) included comparisons 
of drill vs. broadcast seeding; barley as a nurse crop vs. no nurse 
crop ; seeding at varying rates per acre and at different dates ; inocula- 
tion with commercial culture on seed and on soil ; and inoculation by 
soil transfer, wnih and without liming, vs. no inoculation. The 
inoculation by soil transfer in all these investigations was made by 
applying soil from a field in which the particular legume had been 
growing for some years to the plot at the rate of 200 pounds per 
acre and harrowing immediately. From the start the alfalfa on all 
the plots in Field E was thrifty and dark green in color. Examina- 
tion showed some nodules on the roots of plants in the uninoculated 
plots, undoubtedly because of the close proximity of alfalfa in the 
adjoining series, and a great abundance on the plants in the inocu- 
lated plots. Under such conditions the inoculation might be expected 
to show minimum effects. 

The soil in Field F, on the other hand, is in a state of only medium 
productivity. Alfalfa has never been grown nearer than 30 rods 
from the plots used in these experiments. These plots (1/40 acre 
each), 68 in number, were seeded in the spring of 1913. The series 
included duplicate plots for each of the following comparisons : 
Tests of strains of Grimm alfalfa from Minnesota and Montana and 
of commercial stocks of Grimm and Turkestan, of ordinary alfalfa 
from Kansas and Nebraska, and of white sweet clover; drill vs. broad- 
cast seeding ; rye, barley, oats, wheat, and flax as a nurse crop vs. no 
nurse crop ; and the same series of inoculation studies as those in Field 
E. The data showing the results of these different methods of seed- 
ing, covering the crops harvested over a ^eries of years, will be 



1/4 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



presented in another publication. The present paper deals only with 
the crops harvested in 19 14 from the plots on which methods of apply- 
ing inoculating material were compared. On Field F the alfalfa plants 
on the plots to which no inoculating material was supplied showed dis- 
tinct lack of inoculation in 1914 at the time the first and second 
cuttings were made. Later in the season some plants in the uninocu- 
lated plots were found to have nodules on their roots. 

As will be noted, there are 3 plots of each treatment, 2 in Field F 
and I in Field E. The 3 cuttings of the plots in Field E were made 
on June 10, July 20, and September 9, respectively. Those in Field F 
were made on June 18, July 26, and September 9. Each cutting was 
cured in cocks and protected against rain by canvas covers. When 
thoroughly field cured, the hay from each plot was weighed and a 
representative sample taken to the laboratory for determinations of 
dry matter and protein content. The yields, calculated to the basis 
of pounds per acre, are shown in Table i. 

Table i. — Effect of Different Methods of Inoculation of Alfalfa on Yield of 

Dry Matter per Acre. 



Method of Inoculation. 



Plot 
No. 



First Cutting. 



Cured 
Hay. 



Moist- 
ure. 



Dry 
Mat- 



Second Cutting. 



Cured 
Hay. 



Moist- 
ure. 



Dry 
Mat- 
ter. 



Third Cutting, j -p^^ai 
Yield 



Cured 
Hay. 



Moist- 
ure. 



Dry 
Mat- 
ter. 



Dry 
Mat- 
ter. 



None. 



Commercial culture 
applied to seed 



Commercial culture 
applied to soil 



Soil from alfalfa field . 



Soil from alfalfa field 
+ 2 tons limestone 
per acre 



None + 2 tons lime- 
stone per acre 



18, 52 
Ave. 

12 

24. 58 
Ave. 

13 

25. 59 
Ave. 

14 

26. 60 
Ave. 



15 

27, 61 
Ave. 

16 

28, 62 
Ave. 



Lhs. 
3.783 
3>ooo 



% 
18.9 
28.5 



4.132 
3.020 



14-3 
23-4 



3.928 
3.220 



17.4 
28.6 



4.365 
3.760 



15-9 
25.6 



4.452 
3.840 



22.0 
29.9 



4.568 
3.280 



14.6 
29.2 



Lbs. 
3.068 
2,142 
2,450 

3.541 
2,308 
2,719 

3.244 
2,287 
2,606 

3.671 
2,804 
3.093 



3.472 
2,668 
2,936 

3.901 
2,320 
2,847 



Lhs. 
3.492 
3.260 



% 
23.0 
13-0 



Lbs. 
2,589 
2,700 



3.783 
3.320 



22.8 
II. 7 



3.579 
3.460 



27.8 
10.7 



3.637 
3.520 



23-4 
14.5 



3.404 
3,620 



2,534 
2,560 



Lbs. 
2,689 
2,839 
2,789 

2,920 
2,969 
2.953 

2,584 
3.090 
2,921 

2,78612,473 
3,005 2,500 
2,932 



% 
22.3 
20.7 



19.1 
23.6 



2,502 
2,580 



19-5 
22.4 



Lhs. I 
2,011 
2,150 
2,104 

2,050^ 
2,092 
2,078' 

I 

2,014 
2,002 
2,006 



Lhs. 
7.768 
7. 131 
7.343 

8,511 
7.369 
7.750 

7.842 
7.379 
7.533 



24-3 
20.5 



26.0 2,519 2,269 
8.1 i3.33i 2,680 
13.061 



24.0 ji 



21.8 



3.317 
3.620 



25.0 2,487 2,534 
6.2 3,39612,660 
'3.093I 



23-8 
23-9 



,872 8,329 
,9807,789 
,944 7.969 



724 7.71S 
,096 8,095 
,972 7,969 



.93ij8,3i9 



I, 

2,025j7,74i 
1.994 7.934 



These results show a slight increase in yield in the second and 
third years after seeding due to the inoculation with commercial cul- 



AUNN- AM) III AH I I IK : 1 \ ( )( T I .AT I ( )N ( li' AI.IAI.IA 



'75 



tiiro (the inoculation applied to the seed ])v\\\<^ appari-nlly more 
clYcctivc than that applied to the soil ), and a (juite si^nilicant iiu'rcasc 
from the inoculation with soil from an old alfalfa field, lamin,*,' 
(J.ooo ll)s. «;round limestone per acre) at seeding time, without 
inoculation, appears to he almost as eflicient on these lands as inocula- 
tion. The series on the Ouinn h\arm, outlined helow, show a much 
more pronounced effect of the inoculation in increasing the yield of 
the hay crops the tirst year (second year after seeding) than is here 
indicated. It is interesting to note, however, that a consistent hene- 
ticial effect was found on the 3 separate plots in these series on both 
heavily manured land and soil of medium productivity, extending into 
the third year after seeding. 

It will be observed that, as might be expected, there are occasional 
variations from the general rule in the case of individual cuttings 
from particular plots ; but the next following cutting almost in- 
variably gave correspondingly larger or smaller yields, so as to balance 
up the total yield for the season. Apparently these fluctuations are 
due to some local disturbing influence which prevents the crop from 
utilizing normally the plant food supply in the soil, and the next fol- 
lowing cutting profits or loses by the draught on the soil during the 
growth made by the preceding cutting. 

The results of the determinations of the percentage of protein- in 
the samples from each of the cuttings on each of these plots are 
shown in Table 2. 

These results show a surprisingly consistent effect of the inocula- 
tion at seeding time upon the percentage of protein in the crops cut 
two years later in Field E and one year later in Field F from the 
different plots. As in the case of yields of dry matter per acre, there 
are occasional fluctuations, but these are almost invariably followed 
by a corresponding reversal of relationships in the next succeeding 
cutting. As the determinations of nitrogen upon which these cal- 
culations were based were made by laboratory assistants who had no 
information as to the origin of the samples, or purpose of the in- 
vestigations, the consistency of the results is explainable only on the 
basis of an actual effect of the inoculation in 191 2 upon the chemical 
composition of the crop in 1914. 

2 In all the discussions in this paper, the term protein is used to designate 
what is commonly called " crude protein," i. e., nitrogen X 6.25. All deter- 
minations were made in duplicate, and the results presented are the average of 
closely agreeing duplicates, in every case. 



76 



JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



Table 2.— Effect of Different Methods of Inoculation on the Protein Content 

of Alfalfa. 

(Field E, Series I, Plots 11-16; Field F, Series III, Plots 18-62.) 



Kind of Inoculation. 



Plot 



Percentage of Proiein in the Dry Matter. 



None , 



Commercial culture applied to seed 



Commercial culture applied to soil. 



Soil from alfalfa field 



Soil from alfalfa field + 2 tons limestone per 
acre 



None + 2 tons limestone per acre . 



No. 


First 
Cutting. 


Second 
Cutting. 


Third 
Cutting. 


Average. 


II 
18 
52 
Ave. 


17.58 
15.46 
14.40 
15-81 


16.52 
14.83 
14.30 
15.22 


18.50 
16.48 
18.95 
17-98 


17-53 
15-59 
15-88 
16.34 


12 
24 
58 
Ave. 


14.87 
14.54 
14.50 
14.64 


15.80 
16.25 
14.49 
15-51 


17.98 
19.57 
19.64 
19.06 


16.22 
16.77 
16.21 

16.40 


13 
25 
59 
Ave. 


17-94 
15-35 
16.25 
16.51 


16.08 
15-37 
14.88 
15-45 


19.83 
17-43 
19-57 
18.94 


17.95 
16.05 
16.90 
16.97 


14 
26 
60 
Ave. 


18.53 
15-49 
15-99 
16.67 


15-03 
14.98 
14.70 
14.90 


18.41 
19.64 
20.21 
19.42 


17-32 
16.70 
16.97 

17-00 


15 
27 
61 
Ave. 


19.25 
16.94 
17-63 
17.94 


15-19 
16.08 
15-83 
15-70 


20.58 
19.48 
21.17 
20.41 


18.34 
17-50 
18.21 

18.02 


16 
28 
62 
Ave. 


17-56 
17.17 

I4;7I 
16.48 


15.99 
16.26 
12.07 
14.78 


19.01 
18.25 
19.06 
18.74 


17-52 
17-23 
15.28 
16.67 



Second Series, Quinn Farni, Inoculation of Alfalfa by Transfer of 
Soil from Sweet Clover and Alfalfa Fields, with and zvithout Lim- 
ing. — The soil in this series has received no manure for many years. 
It is low in productivity as compared with the soils on Fields E and F. 
No alfalfa had been grown within half a mile of the field. Twenty- 
three dupHcate plots of i/i6-acre each were seeded, one of each pair 
with alfalfa and the other with sweet clover. Every other plot in 
each set is an untreated check plot, and the treated plots are so 
arranged that in each set there are 11 check plots. At seeding time 
there was applied to 3 plots 200 pounds per acre of soil from an old 
alfalfa field. Similar applications of soil were made to 3 other plots, 
and in addition 2,000 pounds per acre of ground limestone were ap- 
plied. There were also 3 plots to which 200 pounds per acre of soil 
from an old sweet clover field were applied, and 3 plots to which 



.\K\N \\i> rii\uiiii\: 1 \( )( n . IN <>|- \i !• \i !■ \. 



'77 



swccl cloMT soil aiul Imu'sioiu- wi'ir added. I ln' allalla and swccl 
cl()\cr were sown in April. i<)i,v ^^itli 2 hushcls ot oats pei" acre as a 
nurse crop. The allalla was Turkestan, and the sweet elovei-, tlie 
while-tlow ei-ed , strain. i'he in sults reported, therefore, aic for the 
first ero]). taken in the second season from the time ol seedini;. 

( )hser\atiou of the serii^s of plots earl\' in the season showed some * 
lack of uniformilv in the growth on the dilVerent eheek ])lots. Near 
the ccnlor of the scries a j^rouj) of adjacent plots was found on which 
the o-rowth on the check plots was fairly uniform in ai)pearance and 
([uantitv. Mve plots, includiuL;- 3 check ])l()ts and i each which had 
heen inoculated with soil from an old alfalfa field and from an old 
sweet clover field respectively, were selected for the purposes of 
this investigation. All of these plots except the checks were limed 
at seeding time with 2,000 pounds ground limestone per acre. The 
plots were harvested and sampled as described for the preceding 
series. The alfalfa was cut on June 22, July 27, and September 12. 
The single cutting of sweet clover was made on June 22. 

The yields per acre of cured alfalfa hay and of dry matter secured 
from these plots are shown in Table 3. The yields of dry matter 
from the sweet clover plots are included with the results of the 
analyses of the samples of hay in Table 7, in order to save repetition 
in tabulation. 



Table 3. — Effect of Inoculation of Alfalfa with Soil from Sweet Clover Field 
and from Alfalfa Field on Yield of Dry Matter Per Acre. 



Plot No. 


Kind of Inoculation. 


First Cutting. 


Second Cutting. 


Third Cutting. 


Total Yield 
Dry Matter. 


Cured 
Hay. 


Moist- 
ure. 


Matter. 


Cured 
Hay. 


Moist- 
ure. 

Dry 
■Matter. 


Cured 
Hay. 




Dry ] 
Matter. 






Lbs. 


% 


Lbs. 


Lbs. 


% \Lbs. 




% 


Lbs 


Lbs. 


12 


None 


598 


12.9 


521 


573 


5-8 540 


264 


18.0 216 


1,277 


13 




1,518 


17.2 


1,258 


1,320 


II. 8 1,164 


766 


20.8 


606 


3,028 


14 


None 


523 


16.3 


438 


921 


io.'6 822 


509 


16.8 


423 


1,683 


17. 


With alfalfa soil 


1-245 


22.1 


980 1,518 


13.2 1,317:977 


25-9,725 


3,022 


20 


None 


423 


19.7 


340 


722 


10.5 646:370 


i7-3'307 


1,293 



The results show a regular and very large increase in yield of 
alfalfa in the second year after seeding as a result of inoculation. 
They show also that inoculation with soil on which sweet clover has 
been grown is equally efficient with that on which alfalfa has been 
grown in producing this result. The same effect upon the growth 
of the sweet clover is shown in Table 7 (which see). 



1/8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The results of the determinations of protein in the hay from these 
plots are shown in Table 4. 



Table 4. — Effect of Inoculation on Protein Content of Alfalfa. (Quinn Farm.) 







Percentage of Protein in the Dry 


Matter. 


Plot 


Kind of Inoculation. 


First 


Second 


Third 




No. 


Average. 






Cutting. 


Cutting, 


Cutting. 


12 


None 


11.99 


12.35 


13.45 


12.60 


13 


With sweet clover soil 


18.53 


13.87 


14.96 


15.79 


14 




14.94 


12.20 


11.67 


12.60 


17 


With alfalfa soil 


17.81 


13.48 


15.46 


15.55 


20 • 




12.02 


10.03 


16.18 


12.73 



Here, again, a very marked influence of the inoculation is shown. 
The percentage of protein in the dry matter from the inoculated plots 
was uniformly considerably higher than in that from the uninoculated 
ones. As in the first series, an occasional variation appears, which is 
accompanied by a corresponding change in composition in the follow- 
ing cutting from the same plot. 

It appears from the data shown in Tables 3 and 4 that on the soil 
of central Minnesota, as represented by these three fields of soil of 
varying productivity on the University Farm, a very significant in- 
crease in both the yield and protein content of alfalfa in the second 
year after seeding results from applying at seeding time soil on which 
either inoculated alfalfa or white sweet clover plants formerly have 
been grown. That this efifect extends over into the next succeeding 
year, but in a diminished degree, is indicated by the data presented in 
Tables i and 2, 

At the same time that the analyses of the above-described samples 
were being made, there was sent in to the laboratory a series of 
samples of the first cuttings from plots of alfalfa grown on the 
demonstration farm at Monticello, Minn., on which a series of com- 
parative inoculations precisely similar to those on the plots in Fields; 
E and F on the University Farm had been made. In this series, 
duplicate plots seeded in the spring of 1913 were given the treatment 
with commercial culture on seed, with alfalfa soil, with alfalfa soil 
plus lime, with lime alone, and check plots left untreated, usmg the 
same quantities per acre as on the plots on University Farm. The 
samples represented the first cutting taken from these plots in the 
second year after seeding. The percentage of dry matter in these 
samples and of protein contained in it was determined. The results 
are shown in Table 5. 



Auw AM) r 1 1 \ K 1 1 11^ : I N( i( n . \ ri< IN <>h \i i m !• \ 



'79 



Taki.k 5. — I'lfi 


(■/ ('/ 

( I' icld 


)cnlatu>it lui 
N, Mt)nlicc' 


I'lii'i'in ( 
lo, Minti. 


nillrill oj .lljiilfn. 

) 


■1 

F 

■ Kind ol Inoi ulation. 




Percentage of i'micin in 


the 1 )i y Matter. 




Plot No. 


Percent. 


Plot No. 


Percent. 


Average. 


A Haifa soil + lime. . . . 


I 


23.07 




23 46 


23.26 


Alfalfa soil 


2 


24.75 


7 


24.17 


24.46 




3 


18.16 


8 


17-30 


17.73 


Commercial culture.. . 


4 


20.46 


9 


21.70 


21.08 


None + lime 


S 


25.183 


10 


21.65 


21.65 



The same effect of the (htYerent treatments upon the percenta^^e of 
l^rotein in the (h-y matter as was found in the other series ap])ears in 
these results. The actual quantitative effect is different, as might 
be expected from the different soil and environmental conditions 
under which the crop w\as grown, but the same general effect is to be 
observed. 

It appears from all the data presented above that both the yield of 
dry matter per acre and the percentage of protein contained in it are 
increased by the several treatments. Both of these effects would, of 
course, increase the total yield of protein per acre. The actual 
amount of this increase for each of the several different treatments 
and in the different years of growth represented by the 3 dift"erent 
series on the University Farm is showai in Table 6. 



Table 6. — Effect of Different Methods of Inoculation of Alfalfa on Total Yield 

of Protein Per Acre. 



Kind of Inoculation. 


No. of 
Plots. 


No. of 
Cuttings. 


Average Yield per Acre. 
Dry Matter. | Protein. 


Field E, Series I, and Field F, Series III 






Lbs. 


Lbs. 


None 


3 


3 


7.343 


1,191 


Seed inoculated with commercial culture . 


3 


3 


7.750 


1,241 


Soil inoculated with commercial culture . . 


3 


3 


7.533 


1.239 


Soil inoculated with alfalfa soil 


3 


3 


7.969 


1.335 


Soil inoculated with alfalfa soil + 2 tons 










limestone per acre 


3 


3 


7.969 


1,406 


None + 2 tons limestone per acre 


3 


3 


7,934 


1,281 


QuiNN Farm 










None 


I 


3 


1.277 


159 


Soil from alfalfa field 


I 


3 


3.028 


485 


None 


I 


3 


1.683 


215 


Soil from sweet clover field 


I 


3 


3.022 


472 


None 


I 


3 


1.293 


155 



2 Omitted from average, sample badly discolored and showing signs of fer- 
mentation. 



l80 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Effect of Inoculation of Szueet Clover zvith Soil from Alfalfa and 
from Sweet Clover Fields. — The treatments and methods of harvest- 
ing and sampling of the plots of sweet clover on the Quinn Farm 
have been described above. The single cutting of hay which the plots 
afforded was made on June 22. The yields of cured hay and of dry 
matter per acre, the percentages of protein in the dry matter, and the 
yields of protein per acre from these plots are shown in Table 7. 



Table 7. — Effect of Different Methods of Inoculation of Sweet Clover on 
Yield and Protein Content of the Crop. 



PlotNo. 


Kind of Inoculation. 


Yield. 


Protein Con ent. 


Cured Hay 
per Acre. 


Moisture. 


Dry Matter 
per Acre. 


Tn Dry 
Matter. 


Total per 
Acre. 






Lbs. 


Percent. 


Lbs. 


Percent. 


Lbs. 


12 


None 


240 


46.7 


128 


17.04 


22 


13 


With sweet clover soil . . . 


1,664 


27.4 


1,208 


15-76 


190 


14 


None 


240 


37-2 


151 


15-93 


24 


17 


With alfalfa soil 


2,048 


48.9 


1,046 


14.76 


154 



The results in Table 7 show a very marked effect of the inocula- 
tion upon the growth of sweet clover. The yield of dry matter was 
enormously increased, while the percentage of protein in the. dry 
matter, contrary to the results with alfalfa, was decreased by inocula- 
tion with either alfalfa soil or sweet clover soil. Other plots of the 
series which had received these same treatments showed similar effects 
upon the yield of hay, but the check plots in these other portions of the 
series were so irregular in their growth and yield that the results 
were inconclusive. The data presented in Table 7 are insufficient to 
permit definite conclusions, but since they are confirmed by the addi- 
tional data presented in Part II of this paper, they are deemed worthy 
of consideration and are therefore presented at this time. 

II. The Effect of Inoculation on Yield and Composition of 
Tops and Roots of Alfalfa and Sweet Clover. 

In order to ascertain the effect which the application of soil con- 
taining the proper bacteria at seeding time has upon the actual de- 
velopment of individual plants, the following procedure was under- 
taken. Among the plots on the Quinn Farm in which both alfalfa 
soil and sweet clover soil had been used for inoculation of each of 
these crops, adjacent plots were selected on one of which soil had 
been supplied at seeding time with its own particular type of bacteria 
and the other left as an untreated check plot. On each of these 4 



\lv'\N \\l> IIINICIMK: I XMX ll. a IION Ol'" Al.l' A. 



iSi 



plots, srii.ii.ilr .irr.is ol rxacll) I s(|uari' yard wcw measured at 
different j)laees in eaeli plot wlieic the stand ot |)lants api)eared iiiii- 
I'orni and ot about the a\era_54e thiekness tor the entire plot. In eaeh 
of these I J s(|uare-\ ar(l traets, the whole number of ])lants was earc- 
fully washed and dui^- out, so as to secure as com])letely as pf)ssil)lc 
the entire top and root {growth of all the |)lants. The total number 
of i)lants from each tract was counted and the lops and roots cut 
apart and baj^i^ed sei)arately. These samples, consisting- in each case 
of the entire i^rowth of toj)s or roots from a sinj^le scjuare-yard tract, 

Table 8. — Effect of Inoculation on Groivth of Tops and Roots of Sweet Clover 

and of Alfalfa. 

Sweet Clover. 















Total 
Dry 
Matter. 


Dry Matter per Plant. 


Plot 
No. 


Treatment. 


Sq.Yd. 

No. 


No. of 
Plants. 


Part of 
Plants. 


Green 
Weight. 


Tops 
and 
Roots. 


Total. 


Average, 
for Plot. 












Grams. 


Crams. 


Grams. 




Grams. 




Grains. 


13 


Inoculated 


I 


70 


Tops 
Roots 


2,128 


362.9 
85-8 


5.184 
1.226 




■ 6.410 










422 












2 


91 


Tops 
Roots 


3.150 
791 


519.8 
149.6 


5..712 
1.644 




■ 7.356 




■ 7-148 






3 


60 


Tops 
Roots 


1,948 
409 


324.0 
76.7 


5.400 
1.278 




■ 6.678 






12 


Not inoculated . . 


4 


113 


Tops 
Roots 


358 
88 


64.1 
23.1 


0.567 
0.204 




\ 0.771 










5 


32 


Tops 
Roots 


136 
30 


18.5 
6.7 


0.578 
0.209 




> 0.767 




• 0.694 






6 


37 


Tops 
Roots 


96 
30 


14-5 
5-5 


0.393 
0.151 




> 0.544 







Alfalfa. 



Inoculated 



20 Not inoculated . 



7 


178 


Tops 


1.590 


357-7 


2.010 






Roots 


655 


177-3 


0.996 


8 


256 


Tops 


1,690 


360.5 


1.409 






Roots 


549 


158.8 


0.620 


9 


180 


Tops 


1,286 


263.7 


1.465 






Roots 


407 


114. 


0.633 


10 


119 


Tops 


138 


32.4 


0.272 






Roots 


59 


22.8 


0.192 


II 


181 


Tops 


233 


54-2 


0.299 






Roots 


104 


35-2 


0.195 


12 


133 


Tops 


246 


64.0 


0.482 






Roots 


99 


36.7 


0.276 



3.006 
2.029 
2.098 

0.464 
0.494 
0.758 



2-344 



' 0.572 



Summary. 

Gain in dry matter per plant due to inoculation, alfalfa 310 

Gain in dry matter per plant due to inoculation, sweet clover 928 

Gain in dry matter per square yard due to inoculation, alfalfa 484 

Gain in dry matter per square yard due to inoculation, sweet clover .... 1,046 



1 82 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

were sent to the laboratory for determinations of green weight and 
percentage of dry matter. The number of plants from each of the 
tracts, the total weight of green material in the tops and in the roots, 
and the corresponding weight of dry matter per square yard and per 
plant, are shown in Table 8. 

The data in Table 8 show, as was to be expected from the total 
yields from the plots from which these sample square-yard tracts 
were taken, a large gain in both tops and roots in quantity of dry 
matter produced in the second year of growth as a result of the in- 
oculation at seeding time. They show further that the gain in 
weight was an actual increase in dry matter per plant and not an" 
increase in the number of plants growing upon the given area of soil. 
During the course of the tabulation of these data, it became apparent 
that the increase due to the inoculation was greater in the case of 
the tops than in the roots of the plants, or, in other words, that there 
was a greater proportion of tops to roots in the plants from the inocu- 
lated plots than in those from the untreated check plots. As soon as 
this became apparent, the actual ratio of dry weight of tops to dry 
weight of roots in each of the i2 samples was calculated, with the 
results shown in Table 9. 



Table 9. — Effect of Inoculation on Ratio of Top to Roots in Sweet Clover 

and Alfalfa. 



Sq. Yd. No. 


Crop. 


Treatment. 


Ratio of Dry 
Matter in Tops 
to Roots. 


Average for Plot. 
Plot No. 1 Ratio. 


I 


Sweet clover. . . . 


Inoculated 


4-23 


I 








2 


Sweet clover .... 


Inoculated 


3.48 


I 




^ 13 


3.98 : I 


3 


Sweet clover .... 


Inoculated 


4-23 


I 








4 


Sweet clover .... 


Not inoculated 


2.78 


I 








5 


Sweet clover. . . . 


Not inoculated 


2.77 


I 




■ 12 


2.72 : I 


6 


Sweet clover. . . . 


Not inoculated 


2.61 


I 








7 


Alfalfa 


Inoculated 


2.02 


I 








8 
9 


Alfalfa 


Inoculated 


2.27 
2.31 
1.42 
I-S3 
1.74 


I 
I 
I 
I 
I 




► 17 

> 20 


2.20 : I 
1.56 : I 


Alfalfa 


Inoculated 


10 
II 
12 


Alfalfa 


Not inoculated 


Alfalfa 


Not inoculated 


Alfalfa 


Not inoculated 







Table 9 shows that in each individual case, with both the alfalfa 
and the sweet clover, the ratio of tops to roots was greater in the in- 
oculated plot than in the untreated check plot. From this it appears 
that the beneficial effect of the inoculation upon the yield of hay is 
due not only to an increase in the total dry matter elaborated by each 
individual plant (as shown in Table 8), but also to the deposition of 



AKiW AND I"IIAI( III';K : 1 .\(»( 11. A I ION <»!• AI.I AI.I A. 



a j^^roater ])r()|)()iii()n of llic material maim fai-turc'(l in the ahovc- 
j^rouiid porlioti of tlio ])lants. 

The a])()VO-nKMiti()iU'(l facts made it desirahle to determiiu-, if pos- 
sihlc. whether the iiiocuhited plants were aelually making more effi- 
cient use of the plant food constituents which they were ohtainin^^ 
in the manufactm'e of dry matter, or whether they were simj)ly ahle 
to make larger draui^hts on the soil hecause of the increased vi^or of 
growth induced hv the inoculation. .Accordingly,* determinations were 



Tahlk 10. — liffcct of Inoculation on Plant Food Constitiicnls in 'fops and 
Roots of Sweet Clover and Alfalfa. 



Crop. 

No, 



Treatment. 



13 Sweet clover . Inoculated 



13 



17 



Sweet clover , 



Sweet clover . 



12 Sweet clover. 



17 Alfalfa 



Not inoculated 



Inoculated 



Not inoculated 



Inocu ated 



Alfalfa , 



Alfalfa 



Alfalfa 



Not inoculated 



Inoculated , 



Not inoculated 







Plant Food ConslLiuents (Calculated 


Sq. Yd. 


Part of 


as Percentages of the Dry Matter). 


IN 0. 


Plant. 














Ash. 


Nitrogen. 


P2O5. 


K20. 


I 


Tops 


6.01 


2.28 






2 


Tops 


6.90 


2.63 


\ 1.28 


0.741 


3 


Tops 


7.04 


2.61 


J 




4 


Tops 


12.29 


2.36 






5 


Tops 


11.70 


3-04 


\ 1-23 


1.200 


6 


Tops 


10.78 


1 AO 






I 


Roots 


15.00 


1.30 






2 


Roots 


12.29 


1.50 


)„„ 


0.435 


3 


Roots 


14-57 


1-33 






4 


Roots 


7.63 


1-03 






5 


Roots 


7-05 


1.22 


1 1. 16 


0.950 


6 


Roots 


6.64 


1-34 






7 


Tops 


9-39 


2.57 






8 


Tops 


9-56 


2.52 


1 1.02 


0.999 


9 


Tops 


8.13 


2.46 






10 


Tops 


12.38 


2.09 






II 


Tops 


13.40 


2.01 


1 1-34 


I. no 


12 


Tops 


13-37 


1.91 






7 


Roots 


6.04 


1.74 






8 


Roots 


8.00 


1.72 


1 1-33 


0.730 


9 


Roots 


7.01 


2.10 






10 


Roots 


6.88 


1.32 






II 


Roots 


8.86 


0.88 


y 1. 14 


0.640 


12 


Roots 


7-63 


0.88 







made of the percentage of total ash and of nitrogen, phosphorus and 
potassium in the dry matter in these samples. For the determinations of 
total ash and nitrogen the individual square-yard samples were used, 
while for those of phosphorus and potassium, composites containing 
equal quantities of material from each of 3 square-yard samples of 



184 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

the same plot were used. The results of these determinations, cal- 
culated as percentage of the dry matter and expressed in the terms 
commonly used in reporting analyses of this kind, are shown in 
Table 10. 

The figures for total ash in the dry matter in Table 10 show a very 
remarkable effect of the inoculation in increasing the ash content of 
the roots and decreasing it in the tops of the plants. This effect is 
apparently in other constituents than the phosphorus and potassium, 
however, as the percentage of phosphorus (expressed as P2O5) 
in the dry matter is not significantly affected by the inoculation, while 
that of potassium (expressed as KoO) is higher in the uninoculated 
plants, in both roots and tops, except in the case of the alfalfa roots. 
It appears that some other elements than those which were deter- 
mined in this work are responsible for the wide fluctuations in ash 
content of the inoculated plants as compared with uninoculated ones. 
It seems probable that calcium and perhaps magnesium may be 
largely concerned in this matter, and it is proposed to make a careful 
study of this matter during the coming season. Lack of material 
(particularly from the uninoculated plots) prevented further ana- 
lytical work on the samples used in the above described work. The 
nitrogen content, since these are leguminous plants and hence when 
inoculated draw a considerable proportion of their nitrogen from 
the air by the aid of the symbiotic bacteria rather than from the soil, 
would not be expected to vary in the same direction or proportion 
as the other plant food elements. It is important to note, however, 
that although the roots of the inoculated plants do not show a de- 
cided increase in percentage of nitrogen, the much larger weight of 
dry matter produced by these plants leaves in the soil, as a residue, 
much more organic matter and nitrogen than is left by the roots in 
the uninoculated plots. The value of inoculation from the standpoint 
of effect upon subsequent nitrogen supply in the soil, even on soils 
in as good productive condition as these, is clearly demonstrated. 

The same effects of inoculation that were observed in the samples 
from the various cuttings from the large plots, namely, an increase 
in percentage of protein (or nitrogen) in the dry matter of alfalfa 
and a decrease in that in the sweet clover as a result of the inocula- 
tion at seeding time, are shown in these analyses, the only exception 
being that the root portions of the sweet clover were not significantly 
affected in either direction by the inoculation. 

Finally, the calculated quantities of these constituents present in 
the several samples, expressed as pounds per acre, are shown in 
Table 11. 



\\|! 



I MK l'I.A I ION (II' Al l' \l I \, 



IS:; 



TaulK 11. l:JJi\t (>J I ihUilhllh'ii lii'dii ijlimility of I'ldiit haod I'on.sllllicitl: 
ill ("ro/'.v of S'iCi'ct Clorrr and .llfdljd. 

(A\iMaK(-' <>l tliri-i' s(|uari'-\ar(l plots in cuh tasc.) 



Crop. 



TiriUimiit. l';iit of I'lanty 



l>l:ii>t I'-.Mxl (:..nsliliirnts 1' 



(liams per Square Yard. 



Nitrogen. PjOg. KgO 



rounds per A. i c. 
Nitrogen. Pj^ft- K./J. 



Sweet clover. Inoculated 



vSweet ck)ver . Not inoculated 



Alfalfa Inoculated . . . 



Alfalfa Not inoculated 



Tops 

Roots 

Whole plant 

Tops .' 

Roots 

Whole plant 

Tops 

Roots 

Whole plant 

Tops 

Roots 

Whole plant 



10.05 
1.46 

11.51 
0.86 
0.13 
0.99 
8.25 

2.73 
10.98 
0.99 
0.31 
1.30 



5-15 
1. 17 
6.32 
0.40 
0.14 
0.54 
3-34 
2.03 
5-37 
0.67 
0.36 



2.98 
0.45 i 
3-43 
0.39 
0.1 1 
0.50 

3- 27 
1. 10 

4- 37 
0.56 
0.20 



1.03 I 0.78 



128 



70 38 



60 



49 



14 



The data presented in Tables lo and ii appear to indicate that 
the large increases in dry matter per plant caused by the inoculation 
are due chiefly to the increased vigor of growth and power to absorb 
and utilize plant food constituents from the soil, rather than to 
utilize similar amounts of these elements for the production of in- 
creased dry matter by the plant. This is true at least so far as 
phosphorus and potassium are concerned. The data with reference 
to total ash might indicate some effect in ability to produce much 
larger proportions of dry matter from a given supply of mineral 
material as a result of the inoculation, but the study is not yet suffi- 
ciently complete in this direction to permit any conclusions to be 
drawn from it. We hope to add to the data on this point during 
the coming season. 

The thanks of the authors are due to Miss Cornelia Kennedy and 
Mr. Morris J. Blish for most of the determinations of nitrogen from 
which the data concerning the protein content of these samples were 
computed. 



1 86 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



VARIETAL NAMES OF OATS.^ 

W. C. Etheridge, 
Cornell University, Ithaca, N. Y. 

In connection with the discussion of varietal names of field crops 
in the January-February issue of the Journal of Agronomy/ the 
writer wishes particularly to point out the confusion in nomenclature 
and in forms of oat varieties grown in this country. In attempting a 
classification of oat varieties on a morphological basis it has been 
found that varietal names very often have little or no significance. 
Many different names are applied to the same variety and many dif- 
ferent varietal forms are found under the same name. For example, 
let us consider the vagaries in nomenclature of the widely known 
variety, Swedish Select. 

The Swedish Select oat was introduced into this country from the 
St. Petersburg province of Russia in 1898, by the U. S. Department 
of Agriculture. It had been carried to Finland and Russia from 
Sweden and was thought to be an improved strain, hence the name 

Swedish Select." The distinct worth of the variety under the new 
conditions of this country was soon recognized. At the present time 
it is one of the most popular varieties among northern white oats, 
which perhaps accounts for the multiplicity of wrong names applied 
to it. No description of the Swedish Select was published at the 
time of its introduction beyond the statement that it was a very 
large-grained, white oat."^ The following description of the variety 
as it now exists in this country is therefore given, in order to de- 
lineate the type to which reference is here made. 

Swedish Select. — Culms erect from early growth, medium large, stiff, gla- 
brous ; sheaths dark green with grayish bloom at period of full heading, scarcely 
covering the internodes; leaves colored as sheaths, medium wide,' margins 
smooth; ligules well developed; rachis straight; panicles equilateral, medium 
long, somewhat compact, erect, the branches ascending; 3-grained spikelets usu- 
ally numerous per panicle, sometimes predominating over 2-grained spikelets, 

1 Received for publication April 19, 1915. 

2 Montgomery, E. G., On Naming Varieties, Jour. Amer. Soc. Agron., 7 : 
29-31. 

3 Carleton, Mark Alfred, Russian Cereals, U. S. Dept. Agr., Div. Bot. Bui. 
No. 23, p. 21. 1900. 



I'/ni i.Riixii; : \ aki i: i \i. .\.\mi:s oi' oa i s. 



.87 



i-jirainod spikclots iiol nccurriii)^ ; f^luiiu's dark ki'<-'<.'Ii with ^riiy'-'^'' hlooin at 
poriod of full hoaditiK. usually o ucrvi-d, sonuiiuu's lo-ncrvcd ; Krains white, 
plump, larj^c, the outer j^raius slidit-pointid and on lluir dorsal side very 
concave at about the rej^ion of liu- awn; lemma snidoth, 7-nerved ; awn usually 
present, somewhat twisted hut seldom j^t-niculate. hlaek at hasi-; basal hairs 
absent or seldom occurring, if pri-sent few. weak and short; racliilla 2-3 mm. 
\o\iix. usually furrowed, nearly always glabrous. IMants medium in tnaturing. 
80-90 days. 

The material from which this description was (h-awii is included 
amoiii;- ahout 700 so-called varieties and du])licates collected for clas- 
sification from 40 experiment stations and 53 seedsmen. Amon^ 36 
lots bearing the name Swedish Select," from 22 stations and 8 
seedsmen, only 23 are alike ; and these constitute the variety here de- 
scribed. Of the 22 stations 6 were growing varieties other than 
Swedish Select under that name. Of the 8 seedsmen 2 were selling 
other varieties under the name " Swedish Select." In a few cases 
several widely different forms had been grown as Swedish Select by 
the same station. Among 13 lots which did not conform to the type, 
the forms ranged from varieties closely resembling Swedish Select 
to side panicle oats and, in one case, to Red Rustproof. 

On the other hand, the Swedish Select form occurred among the 
700 lots under 93 different names and variations of names, while 
most of these names were in turn applied to other different forms. 
Frequently the misnomers were " pedigreed " or " selected " numbers 
of various experiment stations. In other cases, such popular names 
as National, Lincoln, Roosevelt, President, Banner, Twentieth Cen- 
tury, Golden Fleece, and Prosperity were applied to the Swedish 
Select and to other different forms as well. 

The confusion in nomenclature and in forms is, however, by no 
means confined to Swedish Select, which is cited here merely to illus- 
trate a fault which is all too common. In fact nearly all forms are fre- 
quently misnamed and nearly all names are applied to different forms. 
Clearly, then, varietal names for oats are to a great extent meaning- 
less and there is no uniform conception of type among experiment 
station investigators or seedsmen. 

The editorial suggestion in the January-February Journal as to the 
difficulty in correlating results of varietal tests is particularly ap- 
plicable to tests of oat varieties. In the present confusion of names 
and forms, a list of varietal names is of little use for indicating the 
actual varietal forms in the list. A single form under various 
names may comprise a large part of the list ; perhaps several forms 
are misnamed ; and in either case the results of the test must be mis- 



1 88 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

leading. It therefore follows that results of many varietal tests are 
actually harmful, for the reason that conclusions from such results 
often place an undue valuation upon an unworthy name or debase 
the name of a high yielding variety by applying it to a worthless 
form. This doubtless has been a large factor in causing the lack of 
uniformity in results of varietal tests. Many failures of varieties 
charged to their lack of adaptation often could be better explained, 
perhaps, by the fact that the variety in question was present in name 
only. 

The ultimate practical end of varietal tests, of course, is to pro- 
vide the farmer with accurate information as to the yielding power of 
varieties ; but wherein lies the propriety of tacitly recommending varie- 
ties by the publication of names which may or may not refer to the 
particular forms which have yielded well in a given test? What as- 
surance is there that farmers, acting on our recommendation, may not 
receive from seedsmen a worthless variety under the name which we 
have recommended? The latter circumstance need not result neces- 
sarily from dishonesty on the part of the seedsman, but rather from 
his ignorance of types. 

There seems to be no better plan for setting right the confusion in 
the nomenclature of crop varieties than that suggested by Professor 
Montgomery, namely, the establishment of an official register for 
these varieties. If varieties now extant could be described accu- 
rately, named officially and registered, we should have not only an 
invaluable reference for the identification of forms, but also an elim- 
ination of the vast confusion of meaningless varietal names. This 
would be the basis for better and more serviceable work in agronomy. 
With the common use of standard types, officially named, we should 
be able to reach definite conclusions regarding the performance of a 
given variety under various conditions. Furthermore, if seedsmen 
were required to register their varieties and permitted to sell them 
only under official names, we might then feel that our recommenda- 
tions of varieties would be justified by practical results. 



189 



ACROXOMIC Al'I'AIKS. 

PROGRAM FOR THE BERKELEY MEETING. 

A lonlativc i)r()^rani for the incctin|L;" of ihv Aiiicrican Society of 
Agronomy on the campus of the University of California, Ik'rkeley, 
has heen arran<>ecl from the titles of |)aj)ers which have been sub- 
mitted to the Secretary. As this is written nearly two months before 
the meeting, it is probable that several additional pa])ers will be avail- 
able, titles of which have not yet been presented. Shifting of papers 
to suit the individual convenience of those presenting them can be ar- 
ranged without difficulty. The program as now planned is as follows : 

Monday Afternoon, August 9. 

1. The Progressive Development of the Wheat Kernel, Dr. R. W. 
Thatcher, Experiment Station, St. Paul, Minn. 

2. Smut Explosions and Fires Occurring during Thrashing in the 
Wheat Fields in Eastern Washington, Prof. E. G. Schafer, Experi- 
ment Station, Pullman, Wash. 

3. Formation and Classification of the Soils of Arid Regions, Prof. 
Chas. F. Shaw, University of California, Berkeley, Cal. 

4. Climatic Effects on Oats, Prof. Alfred Atkinson, Experiment 
Station, Bozeman, Mont. 

Monday Evening, August 9. 
Joint Session with the Society for the Promotion of Agricultural 
Science and the American Farm-Management Association. 

1. Presidential Address for the Society for the Promotion of Agri- ^ 
cultural Science, Dr. H. J. Waters, Kansas State Agricultural Col- 
lege, Manhattan, Kans. 

2. Presidential Address for the American Society of Agronomy, 
Dr. C. E. Thorne, Ohio Agricultural Experiment Station, Wooster, 
Ohio. 

3. Presidential Address for the American Farm-Management As- 
sociation, Prof. Andrew Boss, College of ^Agriculture, St. Paul, Minn. 

Tuesday Morning, August 10. 
I. Breeding Early and Late Strains of IManchuria Barley, Prof. 
C. P. Bull, Experiment Station, St. Paul, Minn. 



190 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



2. A Critique of the Hypothesis of the Lime-Magnesia Ratio, Dr. 
Chas. B. Lipman, University of Cahfornia, Berkeley, Cal. 

3. Relation of Type of Farming to Soil Fertility, D. A. Brodie, 
Office of Farm Management, U. S. Dept. Agr., Washington, D. C. 

4. Soil Nitrogen from the Standpoint of Plant Nutrition, Dr. W. P. 
Kelley, Graduate School of Tropical Agriculture, University of Cali- 
fornia, Berkeley, Cal. 

5. Business Session. 

Tuesday Afternoon, August 10. 
Joint Session. 

1. The Effect of Time of Seeding on Rate of See ling Winter Wheat, 
Prof. W. M. Jardine, Experiment Station, Manhattan, Kans. (A. 
S. A.). 

2. The Practical Application of Farm Management Principles, Mr. 
H. W. Jeffers, Plainsboro, N. J. (Amer. Farm-Mgmt. Asso.) 

3. The Farmer's Response to Economic Forces, Prof. W. J. Spill- 
man, Office of Farm Management, U. S. Dept. Agr. (Amer. Farm- 
Mgmt. Asso.) 

4. Intensive Agricultural Practice of China and Japan, Prof. Al- 
fred Vivian, College of Agriculture, Columbus, Ohio. (S. P. A. S.) 

Tuesday Evening, August 10. 

If a sufficient number of papers are available, a session will be 
arranged. 

MEMBERSHIP CHANGES. 

The membership reported in the May- June number of the Journal 
was 437. Since that time, 7 new members have been received, making 
the total at this date 444. The number of new members received in 
191 5 is now 78. The names of new members not previously reported, 
and recent changes of address are as follows : 

New Members. 

Beavers, J. C, Purdue Agr. Expt. Sta., La Fayette, Ind. 
Gaddis, p. L., Hopt Farm, Cambridge, Nebr. 
Holland, Robt. E., University Farm, Lincoln, Nebr. 
LoRA, Armando, Aguiar 47, Havana, Cuba. 
Noyes, H. a., Purdue Agr. Expt. Sta., La Fayette, Ind. 
Slipher, John A., Purdue University, La Fayette, Ind. 
Spafford, R. R., University Farm, Lincoln, Nebr. 



ACRO.NO.M K" AI' l' AI US. 



Addui'ssi'.s Ciianci:!). 

I i.oi II II u, l\. \\., ()\\Wv ol" I'ann M aiiaKinii-iil, V. S. Dept. .Akt., Washing- 
ton. I). (.'. 
Dki.wu iii:. I-:, j.. Ashland. Wis. 
joNKS. J. W., Ncphi Suhstation. Niphi. Utah. 

Kkaitss. F. G., Siipt. of Extension Work, \']\\)\. Sta., Ilonohihi, ilavvaii. 
Klkin. M. a., College of Agriculture, I'niv. of ( a!., lU-rkeley, ("al. 
Livingston, GkoR(.k. Office of Market.s, U. S. Dept. Agr., Washington, I). C. 
MooMAW, Leroy, Judith Basin Suhstation, Moccasin, Mont. 

NOTES AND NEWS. 

M. A. Braniioii has resigned as president of the University of 
Idaho. 

J. B. Davidson, professor of agricultnral enginecrini^ in Iowa State 
College, has been elected to a newly established similar position in 
California. He will devote the greater part of his time to developing 
a testing plant at the University Farm at Davis to determine the 
fundamental reasons for the efficiency of farm machinery. 

P. L. Gaddis has been appointed an assistant professor of agronomy 
in the Nebraska College of Agriculture. He will be engaged in ex- 
tension work. 

E. J. Iddings, animal husbandman of the Idaho college and station, 
has been made dean of the college to succeed W. L. Carlyle. 

J. S. Jones, who has been chemist of the Idaho station for several 
vears, was recently elected director of that station. 

Millard A. Klein has been appointed instructor in soil chemistry 
and bacteriology in the University of Cahfornia, effective July i. 

F. J. Krauss, formerly agronomist of the College of Agriculture of 
Hawaii, is now superintendent of agricultural extension in Hawaii, 
with headquarters at the experiment station, Honolulu. 

George Livingston, for the past year acting head of the depart- 
ment of agronomy in Ohio State University, resigned in June to 
accept a position with the office of markets in the Federal Department 
of Agriculture. In his new position he will investigate the marketing 
of grain. 

H. C. Price, who has been dean of the college of agriculture of 
Ohio State University since 1903, has resigned, effective at the end 
of the school year. 

J. H. Shepperd, agriculturist of the North Dakota college and sta- 
tion and vice-director of the station, will in the future devote his 
entire time to the work of the station. 



192 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The Ohio legislature has passed a bill abolishing the Ohio Agri- 
cultural Commission, which had charge of all State work in agricul- 
ture, and replacing it by a State Board of Agriculture of 10 members, 
who will serve without compensation. The new board will have all 
the powers of the commission except the control of the experiment 
station, which is governed by a separate body. All extension and 
institute work will be conducted by Ohio State University. The bill 
becomes a law ninety days after it is signed by the Governor. 

The Secretary of Agriculture, in accordance with the appropriation 
act for the Department of Agriculture for the current fiscal year, has 
established the States Relations Service. This service includes the 
Office of the Director, in charge of Dr. A. C. True; the Office of 
Experiment Stations, in charge of Dr. E. W. Allen ; the Office of 
Extension Work in the South, in charge of Mr. Bradford Knapp ; the 
Office of Extension Work in the North and West, in charge of Mr. 
C. B. Smith ; and the Office of Home Economics, in charge of Dr. C. 
F. Langworthy. The work relating to agricultural instruction and 
farmers' institutes is to be included in the Office of the Director. 

COMING EVENTS. 

Under this caption it is proposed to keep standing a schedule of 
coming meetings of various organizations more or less closely con- 
nected with agronomy. Secretaries of such bodies are invited to 
furnish information regarding their meetings. 

American Society of Agronomy. 
Annual meeting. University of California, Berkeley, Cal., August 
9-10, 191 5. (In connection with meeting of Association of American 
Agricultural Colleges and Experiment Stations.) 

American Farm-Management Association. 
Berkeley, Cal., August 9-10, 191 5. 

x\ssociATiON of American Agricultural Colleges and Experi- 
ment Stations. 
University of California, Berkeley, Cal., August 11-13, 191 5- 

Pan-American Scientific Congress. 
Washington, D. C, December 27, 191 5 — January 8, 1916. 

Society for the Promotion of Agricultural Science. 
Berkeley, Cal., August 9-10, 191 5. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. 7. September-October, 1915. No. 5. 



THE INFLUENCE OF CERTAIN ORGANIC MATERIALS UPON 
THE TRANSFORMATION OF SOIL NITROGEN/ 

R. Claude Wright, 
Bureau of Plant Industry, U. S. Department of Agriculture. 

Introduction. 

In view of the fact that under ordinary farm practice much organic 
material in the form of fresh and rotted stable manure and green 
manure in various stages of growth is plowed into the soil each year, 
it seems of considerable importance that the influence of these and 
similar materials upon the nitrogen content of the soil should be 
more extensively studied. Further, the plowing under of straw and 
like material which, although not widely practiced, is somewhat ex- 
tensively followed in the citrus belt of southern California, offers 
some interesting problems of practical importance along this line. 
The reason for this latter practice is to maintain in the soil a supply 
of organic material that is more or less resistant to the very rapid 
oxidation which occurs there. 

A few investigators have studied the effects of various nitrogenous 
and non-nitrogenous organic materials upon plant growth, both in 
pots and in the field. Chirikov and Shmuk^ added sugar, starch, 
and straw in amounts varying from 0.125 percent to i.o percent in 
sand cultures. It was found that the least growth of mustard was 
obtained in the presence of sugar, followed by starch and then straw. 
The inhibited growth was evidently due to the reduction of available 

1 Received for publication July 10, 191 5. 

- Chirikov, F. V., and Shmuk, A. A., Abstract in Monthly Bulletin of Agri- 
cultural Intelligence and Plant Diseases, 4 (1913), No. 10, p. 1528-9. 

193 



194 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



nitrogen to insoluble form. F. von May^ reports an experiment in 
which rye straw, red clover hay, and cottonseed meal were plowed 
under singly and in combination. Potatoes were planted immediately 
thereafter. The results showed that nitrification or the rendering 
available of assimilable nitrogen was depressed by the presence of 
more or less nitrogen-free organic matter, such as straw in this case. 
The author suggests that the immediate appropriation of soluble 
nitrogen by microorganisms using the nitrogen-free substance as a 
source of energy is responsible for the depression of plant growth. 
Stutzer* added to pots growing buckwheat i percent each of starch 
and chopped straw. Both materials depressed the yield ; however, 
when sodium nitrate was added, the growth was somewhat improved. 
E. von Seelhorst and W. Freckman^ report a depressed growth of 
oats in pots containing additions of straw or strawy manure. 

Green manures, when plowed under in an immature state, are not 
generally considered to be injurious to succeeding crops. Hutchin- 
son and Milligan*^ report that the best results were obtained when 
Crotalaria juncea used as a green manure was turned under when 
still green and succulent. When plants four weeks old were turned 
under 67 percent of the nitrogen content was nitrified, while with 
plants ten weeks old only 34.5 percent was nitrified. Kellerman and 
Wright^ report that when added to a California soil under laboratory 
conditions mature barley straw reduced the nitrate content of the soil 
from 0.445 to 0.247 mg. per gram of soil, while additions of imma- 
ture green barley and green vetch caused a rapid increase in, the 
nitrate. When i percent of straw was added to the same soil in pots 
growing orange or grapefruit seedlings, marked evidences of nitrogen 
starvation soon became evident by a yellowing of the leaves and 
suspended growth. When 0.02 percent of nitrogen as sodium nitrate 
was added with the straw, the seedlings remained normal. In pots 
of ordinary greenhouse potting soil i percent quantities of straw 
and cellulose produced very marked symptoms of nitrogen starvation 
on grapefruit seedlings, while the same quantities of green sweet 
clover and green grass produced slight chlorotic symptoms only the 

3 May, F. von, Mitt. Landw. Lehrkanz. K. K. Hochsch. Bodenkul. Wien, 2 
(1914), No. 3, p. 433-54- 

4 Stutzer, A., Jour. Landw., 55 (1907), No. i, p. 81-91. j 

5 Seelhorst, E. von, and Freckman, W., Jour. Landw., 52 (1904), No. i-2,i 

p. 163-71. I 
^ Hutchinson, C. M., and MilHgan, S., Agr. Research Inst., Pusa, Bui. 4o| 

(1914), pp. 31. I 
7 Kellerman, K. F., and Wright, R. Claude, U. S. Dept. Agr., Jour. Agr.; 

Research, Vol. II, No. 2, p. 101-13. 1914. j 



w'KKiiri-: I M'l.ui-.Nri': oi- ouc w ic m .\'i i;ki a[,s ox n ituociim. 195 



first few days, followed by a return to the normal e()n(litif)n of 
healthy j:^rowth. At the elose of the experiment, after 166 days, the 
sce(llinu:s treated with straw showed evidences of not recovering from 
the treatment. 

Ri'SF.Aucir. 

Certain experiments were eondueted by the author in order to 
follow the various stag^es of nitroi^en transformation in soil in th(> 
presence of a variety of organic material. Duplicate analyses of 
samples were made periodically while the soils were kept under 
control laboratory conditions at a temperature ran^^ino; from 28 to 
30° C. All nitrates were determined by the modified Tieman-Schulzc 
method,^ Total nitrogen determinations were made by the Kjeldahl- 
Gunning-Jodlbauer method, using the sulphate mixture during diges- 
tion recommended by Lipman and Sharp. ^ 

In the first experiment a study was made of the effect upon 
nitrification in soil of 2 percent and 5 percent quantities of dried 
fresh and rotted stable manure and mature wheat straw. This was 
carried on in both sandy loam and clay loam soil from the Arlington 
Farm near Rosslyn, Va. As these soils both gave an acid reaction, 
this w^as corrected with i percent of calcium carbonate. A large 
quantity of the air-dry soil was first screened and thoroughly mixed 
and 2,000 gram quantities weighed out into large battery jars. After 
the required amount of dried and finely ground organic material and 
1.6 gm. of ammonium sulphate had been mixed in, the samples were 
brought to the optimum moisture condition and incubated eleven 
weeks. The moisture condition was maintained by a layer of wet 
cotton kept over the jars. Every week the contents of each jar was 
thoroughly mixed and 100 grams removed for analysis. After four 
weeks' incubation, the supply of ammonium sulphate having become 
exhausted, a new supply w^as added. The results of the analyses 
are shown in Table i. 

The results of periodic analyses of these samples shown in Table 
I indicate that during the first four weeks nitrification in sandy loam 
was stimulated by 2 percent of fresh manure and slightly depressed 
by 5 percent as compared with that in the control samples. In clay 
loam nitrification was somewhat depressed by 2 percent and greatly 
depressed by 5 percent of fresh manure. Rotted manure in both soils 
stimulated nitrification, with little difference shown between 2 percent 
and 5 percent amounts. In the presence of straw, nitrification in both 

sCentbl. Bakt, Abt. II, Bd. 38 (1913), P- 14-25- 

9 Lipman, C. B., and Sharp, L. T., Centbl. Bakt, Abt. II, Bd. 35 (1912), p. 648. 



196 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

types of soil was totally absent except with 2.0 percent in clay loam 
where slight nitrification was evident. 

Table i. — Nitrification in the Presence of Fresh Manure, Rotted Manure, and 
Straw in Sandy Loam and Clay Loam, Expressed in Milligrams of 
Nitrate Nitrogen per Gram of Dry Soil. 
Sandy Loam. 



Treatment. 


Week. 


Weeks. 


Weeks. 


Wetks. 


V) 


in 


7 

Weeks. 


tn 

CO 




in 

M <U 


Weeks. 




Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Control ' . . . 


0.004 


0.015 


0.035 


0.048 




0.328 


0.344 


0.355 


0.342 


0.349 


0.368 






+2% fresh manure. . 


0.013 


0.037 


0.067 


0.086 


0.067 


0.185 


0.340 


0.437 


0.480 


0.520 


0.508 


+ 5% " " ■• 


0.006 


0.020 


0.024 


0.040 


O.III 


0.388 


0.416 


0.409 


0.435 


0.426 


0.437 


+2% rotted manure. 


0.005 


0.053 


0.074 




0.287 


0.530 


0.525 


0.532 


0.457 


0.527 


0.526 


+5% " " • 


0.025 


0.068 


0.074 


0.105 


0.262 


0.429 


0.427 


0.417 


0.418 


0.445 


0.444 


+2% straw 


0.002 


0.000 


0.000 


0.000 
0.000 


0.007 0.148 
0.000'O.ogo 


0.216 


0.163 
0.187 


0.169 
0.182 


0.192 
0.189 


0.227 
0.193 


+5% " 


0.000 


0.000 


0.000 


0.160 



Clay Loam. 





0.031 


0.100 


0.115 


0.149 


0.332 


0.575 


0.633 


0.610 


0.625 


0.615 


0.630 


+2% fresh manure. . 


0.039 


0.095 


0.109 


0.130 


0.213 


0.449 


0.643 


0.640 


0.640 


0.625 


0.675 


+5% " " •• 


0.014 


0.009 


0.015 


0.033 


0.152 


0.445 


0.475 


0.465 


0.420 


0.494 


0.460 


+2% rotted manure. 


0.053 


0.170 


0.161 


0.212 


0.000 


0.580 


0.725 


0.730 


0.720 


0.790 


0.734 


+5% " " • 


0.093 


0.183 


0.179 


0.200 


0.000 


0.666 


0.770 


0.725 


0.750 


0.730 


0.755 


+2% straw 


0.015 


0.010 


0.016 


0.029 


0.144 


0.362 


0.490 


0.480 


0.465 


0.512 


0.518 


+5% " 


0.000 


0.000 


0.000 


0.000 


0.027 


0.210 


0.305 


0.312 


0.306 


0.332 


0.372 



After the second addition of ammonia, nitrification became more 
rapid in all samples. This was probably due to the fact that de- 
composition of the carbonaceous materials was well advanced. 

After eleven weeks' incubation, both types of soil treated with 
rotted manure contained the greatest amount of nitrate nitrogen. In 
sandy loam treated with fresh manure there was almost as much 
nitrate as with rotted manure present. More nitrate was present 
with 2 percent than with 5 percent fresh manure. In clay loam there 
was considerably less nitrate with fresh manure than with rotted 
manure. With 5 percent there was less than in the controls. All 
samples treated with straw contained less nitrate than the controls. 
In conclusion, rotted manure stimulated nitrification from the first. 
Fresh manure and straw at first inhibited nitrification until de- 
composition was well advanced. 



wuKiiir: 1 N i'iAn-:N(i'. oi- (>K(i.\Mi' m a ri:ui als on \ ni^( 197 

In Iho next exporinuMil . diiplicalc 2 ])crc(.'nt (|uantilics of dried and 
ground fresh and rotted horse nianm'e, straw, and stareli were achh-d 
to 500 j^rani sanipk's of a i^reenhonse heneh soil to whieh o. 1 pereent 
of nitro<^en as potassinni nitrate had heen added. The reipiired 
moisture was added and sani])les ineul)ated seven weeks. The fresh 
and rotted horse manures were from the same original sampU\ which 
some months previous to the experiment had l)ecn (hvided and ])art 
immediately dried, while the rest was allowed to decay in a larj::^e 
j^lass jar with frequent moistening and stirring. Nitrate determina- 
tions were made each week with the exception of the fifth w^eek. At 
the end of the fourth week a second addition of organic material 
was made. The results from this experiment are shown in Tahle 2. 



Table 2. — Nitrate Reduction in the Presence of 2 Percent Quantities of fresh 
and Rotted Manure, Strazv, and Starch, Expressed in Milligra))is of 
Nitrate Nitrogen per Gram of Dry Soil. 









2 






6 






Start. 


Week. 


Weeks. 


Weiks. 


Wetks. 


Weeks. 


Weeks. 




Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 




0.550 


0.550 


0.562 


0.560 


0.545 


0.563 


0.530 




0.550 


0.546 


0.618 


0.565 


0.557 


0.595 


0.600 


-|-Fresh manure 


0.550 


0.465 


0.455 


0.448 


0.437 


0.172 


0.160 




0.550 


0.362 


0.292 


0.315 


0.320 


0.000 


0.000 


+Starch 


0.550 


0.074 


0.094 


0.155 


0.210 


0.000 


0.000 



Table 2 shows that while there was some fluctuation in the nitrate 
content of samples containing rotted manure, nitrate reduction did 
not take place. A reduction in nitrate, however, was evident in the 
presence of fresh manure, straw, and starch. This apparently con- 
tinued until a certain stage of decomposition was reached, when, 
where straw and starch had been added, nitrification commenced. 
On the addition of a fresh supply of organic matter rapid nitrate 
reduction again took place until in samples containing straw and 
starch all nitrate disappeared. 

The next experiment was conducted to determine the effect of 
2.0 percent quantities of cellulose (finely cut filter paper), glucose, 
starch, and fresh horse manure (dried and ground) upon the nitri- 
fication of peptone in the soil. Duplicate quantities of these ma- 
terials and 0.48 grams of peptone were added to 400-gram samples 
of clay loam soil similar to that used in the first experiment, and a 
sandy loam soil from an alfalfa plat on the experiment farm near 
Fallon, Nev. Samples were incubated eight weeks. Nitrate de- 
terminations were made each week and are reported in Table 3. 



198 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Table 3. — Nitrification in District of Columbia and in Nevada Soil in the 
Presence of 2 Percent Quantities of Cellulose, Glucose, Starch, and 
Fresh Manure, Expressed in Milligrams of Nitrate Nitrogen 
per Gram of Dry Soil. 
District of Columbia Soil. 



Treatment. 


Start. 


I Week. 


2 

Weeks. 


3 

Weeks. 


4 

Weeks. 


6 

Weeks. 


8 

Weeks. 




Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Control 


0.013 


0.033 


0.085 


0.130 


0.130 


0.173 


0.216 


+Cellulose 


0.013 


0.000 


0.000 


0.000 


0.000 


0.070 


0.079 


+Glucose 


0.013 


0.000 


0.000 


0.000 


0.000 


0.022 


0.044 


+Starch 


0.013 


0.000 


0.000 


0.000 


0.000 


0.028 


0.053 


+Fresh manure 


0.013 


0.013 


0.015 


0.021 


0.082 


0.182 


0.207 




Nevada Soil 














0.000 


0.006 


0.034 


0.093 


0.139 


0.210 


0.271 


+Cellulose 


0.000 


0.000 


0.000 


0.000 


0.000 


0.000 


0.000 


+ Glucose 


0.000 


0.000 


0.000 


0.000 


0.000 


0.008 


0.038 


+ Starch 


0.000 


0.000 


0.000 


0.000 


0.000 


0.000 


0.000 


+Fresh manure 


0.000 


0.000 


0.000 


0.000 


0.000 


0.093 


0.149 



Examination of the results in Table 3 show that nitrification pro- 
ceeded very slowly in District of Columbia soil with fresh manure 
until after three weeks, when it became more rapid. Where cellu- 
lose, glucose and starch were added the original nitrate present was 
reduced and no nitrification took place until after four weeks. In 
Nevada soil nitrification took place only after four weeks in soil con- 
taining fresh manure and glucose, while none took place with cel- 
lulose or starch present. It might be noted here that at the end 
of the first week tests for glucose and starch showed these materials 
had disappeared. 

A complementary experiment to the preceding was conducted in 
which a similar series was run with 0.2 percent of potassium nitrate 
in place of peptone. From Table 4 it may be seen that, while the 
nitrate in the controls in District of Columbia soil fluctuated somewhat, 
there was no great change in the amount. With cellulose, glucose, 
and starch, nitrate was entirely reduced followed by a commencement 
of nitrification where glucose and starch were present. With fresh 
manure present, the nitrate was partially reduced, then nitrification 
commenced. In sandy loam or Nevada soil nitrate in the control 
samples remained almost unchanged. It was entirely reduced in 
presence of glucose and starch, and nearly all reduced in presence of 
cellulose, but the process was more slow. Not quite half the nitrate 
was reduced in presence of fresh manure. Here also the process 
was slow. Where cellulose and starch were present nitrification set 
in after three weeks. A test for glucose and starch after the first 
week showed these substances to have disappeared. 



WKKillT: I NM-'MUCNCI-: Ol- OkCAMC M A'll'.K 1 Al ,S ON NITU(m.|..\. 



'99 




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S-M33M OMJ. 

Wlf/OfV 33^M^ ; 
SU33M OMl \ 

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SM33/f^ OMJ. '. 

S»1M0IV 33ii»l ' 
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200 JOURNAL OF TPIE AMERICAN SOCIETY OF AGRONOMY. 



Table 4. — Nitrification in District of Columbia and Nevada Soils -\- Potassium 
Nitrate in the Presence of 2 Percent Quantities of Cellulose, Glucose, 
Starch, and Fresh Manure. 
District of Columbia vSoil. 



Treatment. 


Start. 


Week. 


Weeks. 


3 

Weeks. 


4 

Weeks. 


6 

Weeks. 


8 

Weeks. 




Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Mg. 


Control 


0.268 


0.249 


0.253 


0.262 


0.267 


0.237 


0.317 




0.268 


0.051 


0.028 


0.000 


0.000 


0.000 


0.000 


+Glucose 


0.268 


0.000 


0.003 


0.010 


0.020 


0.065 


0.072 


+Starch 


0.268 


0.000 


0.000 


0.000 


0.000 


0.007 


0.012 


+Fresh manure. .' 


0.268 


0.117 


0.169 


0.173 


0.189 


0.184 


0.220 




Nevada Soil 












Control 


0.255 


0.251 


0.252 


0.254 


0.256 


0.269 


0.253 


+ Cellulose 


0.255 


0.204 


0.119 


0.094 


0.085 


0.076 


0.080 


+ Glucose 


0.25s 


0.007 


0.000 


0.000 


0.000 


0.000 


0.000 


+Starch 


0.255 


0.201 


0.084 


0.000 


0.000 


0.000 


0.000 


+Fresh manure 


0.255 


0.214 


0.177 


0.153 


0.157 


0.143 


0.157 



Unfortunately in the former experiments it was impractical to 
obtain reliable total nitrogen determinations. It is apparent that 
parallel total nitrogen and nitrate determinations are important to 
follow the complete transformation of nitrogen in the presence of 
various carbonaceous materials in the soil. 

In the following experiment 500-gram samples of a soil from a 
productive orange grove near Riverside, Cal., were mixed with dupli- 
cate 2 percent quantities of mature barley straw, fresh horse manure, 
cellulose (finely cut filter paper), and dextrose. The straw and 
manure had previously been dried and ground. Potassium nitrate 
w^as added to each, bringing the nitrate nitrogen content to 0.942 
milligrams per gram of dry soil. Samples were brought to the 
optimum moisture condition and incubated three months in glass fruit 
jars with perforated tops. Parallel total nitrogen and nitrate de- 
terminations were made in two weeks, two months, and three months. 
The results are shown in Table 5 and in figure 6. The results in 
this and following experiments given as organic nitrogen were ob- 
tained by subtracting nitrate nitrogen from total nitrogen in each 
case. 

As shown in Table 5 and figure 6, even in the presence of an 
excess of nitrate some nitrification occurred in the control samples. 
This was accompanied by a decrease in organic nitrogen, part 
of which was evidently converted into nitrate. However, there 
was an actual loss of total nitrogen equivalent to 0.132 mg. per 
gram of dry soil. With dextrose present there was a marked 



W'Kicirr: i \ i'i.ri:N( i'. oi" dKcw ic .\i a i i.ki ai.s ox m i roci; \'. 201 



'I'aui.k 5. — A ///'('.(/('n J'/ iiiisJ Oniiiilidit in J 'rrsi'iii t' of J I'crcotl (Jiimililic's <>f 
Dextrose, Cellulose. Straw and h'resh Manure, JLxpressed in Milli- 
(jranis per (irani of Pry Soil. 

NiTKATK Nri U()<.l- N. 





Start. 


a W'c. Us. 


J Months. 


3 Months. 


Control 


0.942 


0.970 


0.970 


0.98s 


+ Dextrose 


0.942 


0.24.^ 


0.270 


0.286 


+ rdlulosc 


0.942 


0.622 


0.655 


0.650 


+ St raw 


0.942 


0.790 


0.780 


0.730 




0.942 


0.872 


0.925 


0.907 


Total Nitrockn. 


Control 


1-544 


1-517 


1.442 


1. 411 


+ Dextrose 


1-544 


1. 1 58 


1. 132 


1.065 


+ CellulosQ 


1-544 


I -55 1 


1-593 


1.499 


-|- St raw 


1-558 


1-655 


1.649 


1-534 


+Fresh manure 


1. 716 


1-725 


1. 771 


1.660 


Organic Nitrogen. 


Control 


0.602 


0.547 


0.472 


0.426 


+ Dextrose 


0.602 


0.915 


0.853 


0.779 


+CelIulose 


0.602 


0.929 


0.938 


0.849 


+ Straw 


0.616 


0.865 


0.869 


0.804 


+Fresh manure 


0.774 


0.853 


0.846 


0.753 



reduction of nitrate, amounting after two weeks to 0.699 P^^ 
gram. Of this nitrate nitrogen, 0.303 mg. per gram was converted 
into organic nitrogen — probably existing in some form of protein 
within the cell walls of the bacteria using this as a source of energy. 
Here also examination of the total nitrogen results show a real loss of 
0.386 mg. per gram of dry soil. After two weeks there occurred a 
slight increase in nitrate accompanied by a decrease in organic nitro- 
gen. Much of the nitrogen lost from the soil probably escaped as 
ammonia, as its odor was noticeable during sampling. With cel- 
lulose, straw and fresh manure present the greatest reduction of 
nitrate occurred in presence of cellulose, amounting in two weeks to 
0.320 mg. per gram, followed by little change. With straw this 
reduction amounted to 0.152 mg., and with fresh manure only 0.07 
mg. per gram. Practically all loss of nitrate can be accounted for in 
the gain in organic nitrogen. There was some gain in total nitrogen 
with these substances present, possibly accounted for through a fixa- 
tion of nitrogen. Even in the presence of an excessive amount of 
nitrate in all samples the only serious loss of nitrogen occurred with 
dextrose present amounting to 0.479 nitrogen per gram of soil. 



202 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

In the next experiment 8oo-gram samples of a silty loam soil from 
the Potomac River flats, District of Columbia, and a sandy loam 
soil from near Riverside, Cal., were mixed with duplicate i percent 




a 



i1 

It <^ 
,1111 



1 1 §1 



§ 5 ^ ^ 



•fa 



ll M 



III! 

Sr/f/IW lH afl£E// Py£/ft G/>££f^ i/£TCN/% 



? 5 5 

i M 

^ ^ !2 ol 



Fig. 7. — Influence upon nitrate nitrogen of i percent quantities of straw, 
green rye, and green vetch in California soil (left) and District of Columbia 
soil (right). 




STKAWlf. S/f££/v flY£lfc 6f>E£N rETC»/% 



STffAtV/X 



6f>££AI />r£ /* a/>££N y£TC/tM 



Fig. 8.- 
rye, and 
(right). 



—Influence on total nitrogen in i percent quantities of straw, green 
green vetch in California soil (left) and District of Columbia soil 



quantities of mature wheat straw, young green rye, and green vetch. 
All materials were previously dried and ground fine. Samples were 



wKKiirr: i n I'I.ui'.ncI'; of okcanu m ai i km ,\i,s ox \ ii Iv-* x ,i \ . 20^ 



brought to the j)ro])cr moisture condition and incuhaled lour mouths. 
No nitrate was added. 'Hie ori.<;inal nitrate nitrogen ])reseut in holli 
soils amounted to only o.ooO \ui^. per .L;ram. Total nitroi^eu and 
nitrate nitro«^cn determinations were made each month. The results 
are shown in 1\il)le 6 and in fiQ^urcs 7 to 

Tahlk 6— Nitrogen Transfonnation in Presence of i Percent Quantities of 
Strinv, Green Rye, and Green Vetch, Expressed in Milligrams per 
Gram of Dry Soil. 
Nitrate Nitrogen. 



Soil and Treatment. 


Start. 


I Month. 


2 Months. 


3 Months. 


4 Months. 


California Soil: 














0.006 


0.045 


0.071 


0.109 


0.127 


+ Straw 


0.006 


0.000 


0.000 


0.037 


0.102 




0.006 


0.194 


0.255 


0.272 


0.323 


+Green vetch 


0.006 


0.213 


0.290 


0.316 


0.312 


District of Columbia Soil: 












Control 


0.006 


0.059 


0.075 


0.062 


0.095 


+ Straw 


0.006 


0.005 


0.023 


0.021 


0.060 


+ Green rve 


0.006 


0.195 


0.226 


0.245 


0.332 


+ Green vetch 


0.006 


0.207 


0.224 


0.228 


0.287 


Total Nitrogen. 


California Soil: 












Control 


1. 019 


0.968 


0.918 


0.935 


0.909 


+Straw 


1.047 


0.995 


0.981 


0.933 


0.939 


+ Green rye 


1-355 


1-343 


1.289 


1.322 


I-273- 


+ Green vetch 


1-413 


1-344 


1.324 


1.287 


1.300 


District of Columbia Soil: 












Control 


1.926 


1.802 


1.797 


1.752 


1.795 


+ Straw 


I-95I 


1.905 


I.918 


1.846 


1.850 


+ Green rve 


2.268 


2.260 


2.254 


2.255 


2.185 


+ Green vetch 


2.325 


2.252 


2.245 


2.264 


2.184 


Organic Nitrogen. 


California Soil: 












Control 


1. 013 


0.923 


0.847 


0.826 


0.773 


+ Straw 


1. 041 


0.995 


0.981 


0.896 


0.834 


+ Green rye 


• 1-348 


I.I39 


1.034 


1. 017 


0.950 


+ Green vetch 


1. 417 


1. 131 


1.034 


0.971 


0.987 


District of Columbia Soil: 












Control 


1.920 


1-743 


1.722 


1.690 


1.700 


+ Straw 


1-945 


1.900 


1.895 


1.825 


1.790 


+ Green rye 


2.262 


2.165 


2.028 


2. Oil 


1-853 


+ Green vetch 


2.319 


2.045 


2.021 


2.036 


1-897 



A study of results shown in Table 6 and figures 7 to 9 show that 
nitrification took place in all control samples, also a loss in total 
nitrogen amounting to o.iio mg. per gram of CaHfornia soil and 
0.131 mg. per gram of District of Columbia soil. In California soil 
with straw present the original nitrate nitrogen was reduced and no 



204 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



nitrification occurred until the third month. In District of Columbia 
soil slight nitrification commenced the second month. In both soils 
there was some loss in total nitrogen, amounting to 0.108 mg. per 



/.'too 

% /.3SV 
ID 

Q 

<«. /.2SV 






2.3S0 
230C 

% iJ2S0 

\ 




























^ 2/SC 
\ 

<(; 2yoo 
<a 

^ 2.0S0 

«: 

;^ 2OO0 
















In 






















l./OO 

% 

1 l.OSO 












\ 

N /.ooo 

^ 0.9SO 
^ 0900 






















































K O.BSO 
V> O.B01 
5 0.7S0 
0.7OC 






























































..J 






\\\\ \h\ 1 r ill 

IM^I Usil H^ti 

UsJitS^ 

CH£CA( STRAW /% 6f>EEAff>r£ /Si OREEH t'ETCR/SS 


liili 

COHTROC 


sbII sI^I 
J J J 1 
lull lull lull 

STRAn/f,. e/iEE/v RrE/% cfieeN verzHit 



Fig. 9. — Influence upon organic nitrogen of i percent quantities of straw, 
green rye, and green vetch in California soil (left) and District of Columbia 
soil (right). 

gram of Cahfornia soil and o.ioi mg. in District of Columbia soil. 
With green rye and green vetch present rapid nitrification took place 
the first month, accompanied by a rapid corresponding decrease in 
organic nitrogen. This process continued less rapidly after the first 
month. There was a small loss in total nitrogen in both soils with 
green rye present, amounting to 0.082 mg. per gram of California 
soil and 0.083 ^ng"- ii'^ District of Columbia soil. With green vetch 
the loss was greater, amounting to 0.113 mg. per gram of California 
soil and 0.141 mg. in District of Columbia soil. 

Parallel with the foregoing experiment a similar one was conducted 
on California and District of Columbia soils taken from practically 
the same localities. The exception was that in this series potassium 
nitrate was added to all samples, bringing the nitrate nitrogen content 
up to 0.520 mg. per gram of dry soil. In all other respects the ex- 
periment was conducted in identically the same manner. The results 
are shown in Table 7 and figures 10 to 12. 



wricht: 1 n fiat NCI-: ok oucamc maii kixi.s ox mik'<)(;i \. 205 



T.Mti.K 7. — Nitroijcn Traiisfortnation in / '/■(•.v< H( <• oj 1 rrri cnl (Juaiililirs of 
Stnm\ Green Rye, and iireen I'ciili, Jixf^ressed in Miliujranis per 
dram of Pry Soil. 



NlTRATK NlTUOCKN. 



Soil and Treatment. 


Start. 


I Month. 


3 Months. 


3 Months. 


4 Months. 


California Soil +Nitrate: 


1 












0.520 


0.527 


0.590 


0.561 


0.550 




0.520 


0.473 


0.482 


0. 'JO? 






0.520 


0.515 


0.625 


0.650 


0.700 


-|-Cjr(?cn votcli 


0.520 


0.492 


0.650 


0.670 


0.710 


Oistrict ot Coluniloia Soil 
























Cnntrol 


0.520 


0.525 


0.560 


=^27 




~|~Straw 


0.520 


0.452 


0.460 


0.433 


0.512 


~f"Grccii rye 


0.520 


0.620 


0.677 


0.032 


0.767 


~|~ Green vetch 


0.520 


0.640 


0.640 


0.737 


0.775 




Total Nitrogen. 








California Soil +Nitrate: 












Control 


1.487 


1.470 


1. 417 


1.427 


1. 41 1 


+ Straw 


1. 515 


1.509 


1.460 


1.427 


1.422 


+ Green rye 


1.820 


1.765 


1. 761 


1-755 


1.739 


+ Green vetch 


1.880 


1.725 


1.769 


1.744 


1.786 


District of Columbia Soil 












+Nitrate: 














2.390 


2.355 


2.374 


2.238 


2.217 




2.421 


2.339 


2.326 


2.310 


2.315 


+ Green rye 


2.740 


2. 611 


2.721 


2.634 


2.655 


+Green vetch 


2.792 


2.736 


2.718 


2.702 


2.637 


Organic Nitrogen. 


California Soil + Nitrate: 








! 




Control 


0.967 


0.943 


0.827 


0.866 


0.861 


+ Straw 


0.995 


1.036 


0.978 


0.920 


0.887 


+ Green rye 


1.300 


1.250 


1. 136 


1. 105 


1.039 


+ Green vetch 


1.360 


1-233 


1. 119 


1.074 


1.076 


District of Columbia Soil 












+Nitrate: 












Control 


1.870 


1.830 


1. 814 


1. 711 


1.652 




1. 901 


1.887 


1.866 


1.877 


1.803 


+ Green rye 


2.220 


1-991 


2.044 


2.002 


1.888 


+ Green vetch 


2.272 


2.096 


2.078 


1.965 


1.862 



The results in Table 7 show that not so rapid nitrification as in 
the former experiment took place in either controls or where green 
rye and green vetch were present. With straw present some nitrate 
was reduced, but this was practically recovered by the end of the 
fourth month. The greatest reduction occurred in District of Co- 
lumbia soil. In control samples there was not so much of a loss of 



206 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



total nitrogen in California soil as in the former series, while the loss 
was greater in District of Columbia soil. As in the former series the 



o.aoar 




cof^rf>oc' ST/>Aw/% GfeeAi fire /f. c/>er/v vsrcv/x c»£C/r sr/>Atf/% SJies/v /rre ik s/>££n ^ercH/* 



Fig. 10. — Influence on nitrate nitrogen of i percent quantities of straw, 
green rye, and green vetch in California soil + nitrate (left) and District of 
Columbia soil -|- nitrate (right). 



loss in total nitrogen was greater in District of Columbia soil, amount- 
ing to 0.173 mg. per gram against 0.076 mg. per gram in California 



/90C 

/£se 



/7SO 
/.7O0 

I.6O0- 

/sso- 



,.4 



li 



Ji 

Hill 




e/>££ly lfy£ /% S/>££m f£7X^/% 



sTffA *>- /f, a/>££» Are /-K <s^fs/v yfKwM 



Fig. II. — Influence upon total nitrogen of i percent quantities of straw, 
green rye, and green vetch in California soil + nitrate (left) and District of 
Columbia soil -f- nitrate (right). 



soil. With straw present the difiference in loss in total nitrogen 
amounted to but little between California and District of Columbia 



WKUiiri": 1 N i-LUi-'.Nii-: oi- oucanic m aii.ui als on n i'iu()(;i:n. 207 



soil with and without nitrate i)rc'S(.'nt. W lu-n i^rccn rye was added 
there was praetieallv no (hiTerenei- l)etween the two soils in the 
anionnt of nitrogen lost. However, in California soil the loss was 
i^reater than in the former series, while in Distriet of Colunihia soil 
the loss was ])ractically the same, althoui^h the results were rather 
lluetnatino- and nneertain. With i^reen veteh i)resent the loss was 
greater in District of Colunihia soil, amountin*^- to 0.155 n\^. per 
<^ram. That in California soil amounted to 0.094 m.j^. per ^ram. 
The loss was also ^^reater than when no nitraate was ])rcsent, while 
in California soil it was less. 

In the last experiment reported upon, 400-f^ram samples of a sandy 
loam soil from near Riverside, Cal., were mixed with duplicate i and 
0.5 percent quantities of mature harley straw. Enough potassium 
nitrate Avas added to bring tjie nitrate content to 0.230 mg. per gram 
of dry soil. Samples were incubated one month. The results are 
showai in Table 8. 

Table 8. — Transformation of Nitrogen in Presence of 0.5 and i Percent Quan- 
tities of Straw, Expressed in Milligrams per Gram of Dry Soil. 
Nitrate Nitrogen. 

Treatment. Start. i Month. 

Control 0.230 0.223 

-{-0.5 percent straw 0.230 0.137 

-j- I percent straw 0.230 0.133 

Total Nitrogen. 

Control 0.946 0.784 

+ 0.5 percent straw 0.959 0.932 

-|- 1 percent straw 0.967 0.826 

Table 8 shows that the amount of nitrate reduced by i and 0.5 
percent quantities of straw was practically the same. In total ni- 
trogen there was a loss of 0.141 mg. per gram with 0.5 percent of 
straw against 0.280 mg. per gram with i percent. The loss with both 
quantities of straw present was less than in the controls. 

Conclusions. 

In the light of the foregoing it seems probable that in agricultural 
practice the plowing under, in an undecayed state, of straw or .strawy 
material such as old hay, litter, leaves, stalks, strawy manure, fresh 
stable manure, and even green manures or cover crops that have been 
allowed to become mature or nearly so, will serve to reduce the 
quantity of available nitrogen in a soil. When such a practice is 



208 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



followed only during fall plowing and in a region with a fairly open 
winter, it would be safe to say that a sufficently advanced stage of 
decomposition would be reached by spring not to interfere with 




Fig. 12, — Influence upon organic nitrogen of i percent quantities of straw, 
green rye, and green vetch in California soil + nitrate (left) and District of 
Columbia soil + nitrate (right). 



normal nitrification. Furthermore there probably would be little 
or no leaching away of soluble nitrogen during the fall and winter 
rains. 

Plowing under of green manures presents a different problem 
because very little resistant cellulose material is added. Such suc- 
culent green material is readily attacked by saprophytic micro- 
organisms and rather rapid decay accompanied by vigorous nitrifica- 
tion takes place, thus maintaining the supply of available nitrogen. 



Journal of the American Society of Agronomy. Plate ii. 




Fig. I. — Two heads each, face and edge views, of New Columbia wheat, C. I. 
No. 3476, ? parent (as grown at Arlington, 1913-14) ; Fj of artificial wheat-rye 
hybrid, 1319a (as grown at Arlington, 1913-14) ; rye, C. I. No. 132, parent 
(as grown at Ithaca, N. Y., 1911-12). 




Fig. 2.— Two heads each, face and edge views, of Purple Straw wheat, C. I. 
No. 191 5 (left), as grown in the plat at Arlington, 1913-14, near the hybrid 
plant; and Rimpau rye, C. I. No. 126 (right), as grown in 191 1, under favor- 
able environment ; also, three heads, face and edge views, of the natural wheat- 
rye hybrid No. i (center). The Rimpau variety of rye grew not far from 
wheat, C. I. No. 191 5, the previous year, and is shown here for comparison. 



Journal of the American Society of Agronomy. Plate hi. 




Fig. I. — Two heads each, face and edge views, of Rimpau rye (same heads 
as in PI. II, fig. 2) ; of natural wheat-rye hybrid No. 2; and Purple Straw 
wheat, C. I. No. 191 5, as grown in the plat at Arlington near the hybrid 
plant, 1913-14. 




Fig. 2. — One head each, edge view, of Dawson Golden Chaff wheat, C. I. No. 
1733, as grown in the plat at Arlington, 1913-14, near the hybrid ; F^ of natural 
wheat-rye hybrid No. 3; and Rimpau rye (one of heads shown in PI. II, fig. 2, 
and PI. Ill, fig. I). 



Li:i(iHTv: natural w iii:at-kvk uvukids. 



209 



NATURAL WHEAT RYE HYBRIDS.^ 

CiADK K. Lkigiitv, 
Bureau of Plant Industry, U. S. Diu'Artmknt of Agriculturk. 

Introduction. 

Artiticial hybrids of rye on wheat have been made by many dif- 
ferent plant breeders. The natural hybrid, however, apparently has 
been observed but seldouL The only reported intance of a possible 
natural wheat-rye hybrid, so far as the writer has found, is that cited 
by Fruwirth- (p. 184) as follows: 

" Miczynski ("Kosmos" r. 30. Lwow. 1905) harvested some open fertilized 
seeds which gave when grown individuals which by their long, pressed- 
together glumes and their manner of standing open when in bloom were rec- 
ognized as hybrids. These were, however, more similar to wheat and were 
not pubescent below the head." 

The original article cited is not in the Congressional Library or in 
any other American library so far as ascertained, and has not been 
seen by the writer. It is possible that these plants grown by 
Miczynski were natural wheat-rye hybrids, although the writer has 
never observed wheat-rye hybrids that were not pubescent below the 
head. 

In the summer of 191 4 four separate instances of natural wheat- 
rye hybrids came to the notice of the writer. Three plants were ob- 
served on Arlington Farm, Rosslyn, Va., one by Mr. H. P. Ames, 
one by Mr. T. R. Stanton, and one by the writer. Two heads, also 
undoubtedly wheat-rye hybrids, were sent to the writer in June, 1914, 
by L. Robinson, of Brush Creek^ Tenn., who writes : " Will you 
please tell me what this is? I pulled it out of a field of wheat. It 
has the appearance of wheat and rye both." 

Description of Artificial Hybrid. 
As a basis for the examination of these plants which are beheved to 
be natural wheat-rye hybrids, comparison with an artificial hybrid pro- 
duced by the writer will be made. In the spring of 1913, 11 flowers 

1 Presented at the eighth regular meeting of the Washington (D. C.) Section 
of the American Society of Agronomy, March q, 1915. 

2 Fruwirth, C, Die Zlichtung der landwirtschaftlichen Kulturpflanzen, Band 
4, pp. xvi + 460. Berlin, 1910. 



2IO JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

on a plant of the common red winter wheat, New Columbia, growing 
in a greenhouse of the U. S. Department of Agriculture, were 
emasculated, and two days later these flowers were pollinated with 
rye pollen from a plant of common rye growing in the same green- 
house. P'our seeds were secured from this cross, and from one of 
these a plant was produced the following season (1914) in the field 
nursery at Arlington Farm. The data on the wheat-rye hybrid given 
herewith were taken on this plant. The wheat data were taken on 
plants produced from seed from the plant on which the cross was 
made, sown in the nursery at the same time and near the seed secured 
by this hybridization. The rye data were taken on the heads of the 
plant which produced the seed from which the pollen parent was 
grown. This " grandmother " plant, as it may be called, was found 
growing as a volunteer on waste land at Ithaca, N. Y., in 1912, there- 
fore being grown in a different environment and in a different year 
from the wheat parent and the hybrid. The fundamental botanical 
characters, however, were doubtless not modified thereby, although 
some dimensions were probably somewhat modified. Typical heads 
of each of these parental forms on which the notes were made and 
of the hybrid are shown in Plate II, figure i. 

The heads of the wheat-rye hybrid are longer, narrower and less 
dense than those of the wheat parent, and are in the case under 
consideration completely sterile. Wheat-rye hybrids seldom bear 
seed. 

The spikelets of wheat are 3- to 5-flowered ; of rye 2-, rarely 
3-flowered ; while the hybrid is 3- to 5-flowered. The average num- 
ber of spikelets on 10 heads of the wheat and rye parents were 21.2 
and 27.6 respectively, on the hybrid 24.7. 

The peduncle of wheat is hollow and smooth ; of rye, solid, hairy, 
rough, and small in comparison with wheat ; while the hybrid is either 
soHd in the smaller culms, or with much thickened walls but hollow 
in the larger culms ; also hairy and rough, but less so than rye, and 
is also about intermediate in size. 

The glumes of wheat are ovate, nearly as large as the lemmas, 
several-nerved ; those of rye much smaller than the lemmas, linear, 
one-nerved. The hybrid resembles the wheat parent very much in 
glume character, but is modified to some extent by the rye, the glumes 
being ovate but with sides more flattened than in wheat, and ap- 
proaching the lemmas in size, but not so closely as in wheat. 

The lemmas of wheat are ovate, and keeled only at the apex, while 
those of rye are lanceolate, keeled from apex to base, with the keel 
ciliate. The hybrid resembles wheat more, but the shape and keel 



LHir.UTV: NATURAL W 1 1 KAT-KVE IIVJJUIDS. 



2 I I 



have been inodilicd by vyv, the latter exten(hn<^ fartlier towaid tlie 
base and slaiuhn^ out more slroiiLiiy. 'Tlie lemma iier\'es of ihe 
hybrid are mueh like those of wheat. 

'Jdie iloral envelopes of the wheat are pubcsecnt. The f^lumes of 
the rye are seabrous. the short stiff hairs deereasinii^ from apex to 
base, while the lemmas are smooth exeept on keels and mari^ins, 
whieh are eiliate. The i^lnmes of the hyl)ri(l are ])nl)escent, while 
the lemmas are pubeseent near the ai)ex and on the martdns and 
seabrous elsewhere. 

The awns in the wheat under discussion increase in length from 
about y2 mm. on the basal spikelets to 10-15 ^i^^^- the apical ; those 
of rye increase in length from 2-7 mm. on the lower spikelets to 
35-40 mm. on the middle, then decrease to 5-10 mm. on the apical. 
Those of the hybrid increase in length from about i mm. on the basal 
spikelets to about 30 mm. on the apical, thus resembling wheat in the 
manner of increase, but attaining nearly the full length of the longest 
rye awns. 

We may say then that the hybrid is distinguished from (i) both 
parents by its sterility, head-shape, general appearance and inter- 
mediacy in many characters; (2) from rye very distinctly by the 
shape and character of the glumes and lemmas and by its 3- to 5- 
flow^ered spikelets; and (3) from wheat very distinctly by the solid 
or thick-walled, hairy, rough peduncle. 

The plants found in the summer of 1914 in the wheat plats at 
xA^rlington and the heads sent to the writer from Tennessee will now 
be considered. Data will be given on each of these and comparisons 
made with the known hybrid described above, showing why they are 
believed to be hybrids between wheat and rye. 

Natural Wheat-Rye Hybrid No i. 

This natural wheat-rye hybrid was found in 1914 at Arlington 
Farm, Rosslyn, Va., in a plat of the Purple Straw wheat. This 
wheat had been in plat tests six years or more on this farm. In the 
previous year the wheat with which this plat was sown grew not 
more than 30 feet from a plat of rye. It is also possible that a few 
stray rye plants had grown in the plat of wheat or in the road border- 
ing the end of the wheat plat. For the purpose of comparison a 
wheat plant growing near the hybrid was preserved. The principal 
culm of this wheat plant was as tall as any growing in the vicinity, 
but the main culm of the hybrid was about 4 inches taller. In fact, 



212 JOURNAL OF THE AMERICAN SOCIETY OF AG4. ^OM^. 

this characteristic led to the discovery of all thred of the hybrid 
plants herein described, found at Arhngton Farm. 

The heads of this hybrid plant and of the neighborii g wheat plant 
are shown in Plate II, figure 2, together with two hj^ads of Rimpau 
rye, the variety which may have been the pollen parent of the hybrid. 
These rye heads were grown in a different year and in different 
environment from the hybrid and the wheat. Measurements and 
other data on the wheat and hybrid plants are given in Table i. 



Table i. — Notes on Wheat-Rye Hybrid, Plant No. i, Found in 1914, and on 
a Near-by Plant of Purple Straw Wheat, in a Plat of Which 
the Hybrid Was Growing. 





Culm No. 


Height. 


Spikelets. 


Head Length. 


Spikelets 
with 3 Flowers. 






cm. 




cm. 




Hybrid plant 


I 


154-4 


25 


10 


16 




2 


141-7 


24 


9 


14 




3 


150.7 


24 


9 


14 


Wheat 


I 


144.2 


18 


6.8 


13 




2 


113-5 


18 


6.2 


II 



The peduncles of the hybrid culms are pubescent and scabrous for 
4 and 5 cm. below the head, while those of the wheat are entirely 
glabrous. The shape, nerves and keels of the glumes of the hybrid 
have the same relation to those of the wheat as is noted above in the 
case of the artificial hybrid. The color of the wheat glumes in this 
case, however, is light yellow, while that of the glumes of the hybrid 
is a slightly deeper yellow. The surface of the glumes of both the 
wheat and the hybrid is scabrous, with margins ciHate, diminishing 
upward, although the margins of the glumes of the hybrid are some- 
what more finely ciliate than in the wheat. The lemmas of the 
hybrid also bear the same relation to those of wheat as has been 
noted for the lemmas of the artificial hybrid described above. The 
lemmas of both the wheat and the hybrid in this case, however, are 
glabrous, while those of the artificial hybrid and of the wheat parent 
are more or less pubescent. The awns of the wheat are about i mm. 
long on the lower spikelets and increase upward to about 20 mm. 
on the apical spikelets, while in the hybrid they increase from about 
I mm. on the lower spikelets to 25 to 40 mm. on the apical. One 
kernel was produced on one of the three hybrid heads. It is sorne- 
what shrunken, light red in color, rather long in proportion to its 
width, and about the same width from end to end, with V-shaped 
crease. The kernel as a whole has little resemblance to rye, but 
resembles wheat very much. 



c.iiTv: NATi'kAi. w II i;A'r-m !•: in i;kii»s. 



Natural W ii i; a r- I\\ !•: IIn i'.kid No. 2. 
llybrid No. 2 was fouiul «4r()\\in^- in llu' same plat of wheat as 
was No. I. The heads of the h}hri(l ])lant and two heads of a 
neii^hhorin^' wlieat plant are shown in IMate III. lij^nre 1, to^^ether 
with two heads of Kinipau rye, the variety whieh may have been the 
pollen ])arent of the hybrid. These rye heads were from the 191 1 
crop. This hybrid was entirely sterile but altoi^ether it does not 
vary from hybrid No. i in any essential eharaeter, so a detailed de- 
scription is not considered necessary. In Table 2 some measure- 
ments are given, however, for the two heads of this plant and for the 
heads of a wheat plant growing near. 



Table 2. — Notes on Wheat-Rye Hybrid No. 2, Found in June, 1914, and on a 
Neighboring Plant of Purple Straw Wheat, in a Plat of Which the 
Hybrid Was Growing. 





Culm. 


Height. 


Length of 
Head. 


No. 

Total. 


Spikelets. 

3-Flowered. 






cm. 


cm. 






Hybrid No. 2 


I 


142.8 


9.6 


25 


21 




2 


140.0 


9.3 


25 


17 


Wheat growing near the hybrid 


I 


122.6 


6.6 


17 


9 




2 


107.3 


6.0 


17 


5 




3 


112. 


5-7 


17 


10 



The peduncle of hybrid No. 2 is sparingly pubescent from the head 
to about 1.5 cm. below the head. It is less pubescent than in hybrid 
No. I. The peduncles of the hybrid were colored a somewhat darker 
purple than those of the neighboring wheat plants. 

Natural Wheat-Rye Hybrid No. 3. 
This hybrid was found in a plat of Dawson Golden Chaff wheat. 
The wheat with which this plat was sown had grown the previous 
year in a position not far removed from rye plants. Rye is recorded 
as having grown not more than 20 feet away and it is possible that a 
few plants may have grown closer than this. The plant consisted of 
a single culm, bearing a head that was fully formed but entirely 
sterile. This hybrid head, which is shown in Plate III, figure 2, 
together with a head of Daw^son Golden Chaff wheat from a nearby 
plant and a head of Rimpau rye grown in 191 1, does not differ from 
that of hybrid No. i, described above, in any of the essential char- 
acters that distinguish it as a wheat-rye hybrid. Some slight dif- 
ferences exist, however. The head is not so compact in form; the 
glumes and lemmas average slightly wider, the awns on the upper 



214 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMIC,. 

Spikelets attain slightly greater length, the longest being about 50 mm., 
and the floral envelopes are of a somewhat deeper yellow color than 
those of hybrid No. i. These differences can be attributed to the 
supposed difference in parentage and are in line with the expectation, 
as the floral envelopes of Dawson Golden Chaff are of a deep yellow 
or reddish color, while those of Purple Straw are almost white. The 
form of head also differs slightly, the outer kernels of a spikelet 
standing at a wider angle from each other in the former than in the 
latter variety, which would account for the less compact form of 
hybrid 'No. 3. 

Notes are given on natural wheat-rye hybrid No. 3 in Table 3, and 
also on a plant of the surrounding wheat that was preserved for 
comparison. 



Table 3. — Notes on Wheat-Rye Hybrid No. 3, Found in June, 1914, and on a 
Neighboring Plant of Dawson Golden Chaff Wheat, in a Plat of 
Which the Hybrid Was Growing. 





Culm No. 


Culm Height. 


Head Length. 


No. of Spikelets. 


Spikelets with 3 
or More Flowers. 






cm. 


cm. 






Hybrid 


I 


138.3 


10.5 


25 


19 


Wheat 


I 


128.3 


7-7 


20 


15 




2 


121. 1 


8.5 


19 


13 



The peduncle was pubescent and scabrous for about 12 mm. below 
the head, but decreasingly so from the head downward; walls were 
much thickened and the cavity nearly or entirely closed for some 
distance below the head. The peduncle of wheat was glabrous and 
hollow. 

Natural Wheat-Rye Hybrid from Tennessee. 
As stated previously, two heads were sent to the writer in June, 
1914, from Brush Creek, Tenn. Both of these are entirely sterile. 
In general appearance they are much like the artificial hybrid de- 
scribed above, as the heads are long and the glumes and lemmas are 
pubescent. No statement was made by the sender as to the variety 
of wheat in which this plant was found, but the cross must have been 
of a rye on one of the wheats having pubescent floral envelopes. 
Some of the distinctive characters of the natural hybrid are given 
and comparison made with the artificial hybrid described above. 

Head long, 16 cm. ; 30 spikelets ; sterile ; longer than usual in wheat and 
with more spikelets. Density 0.534 (artificial hybrid .515)- 

Peduncle hairy for 2 cm. below head; scabrous near head; hollow, walls 
fairly thick. Agrees in these with artificial hybrid described. 



ij-.icii'i'v : NATuuAi. wiii'.A'i-in i-: iin i'.kids. 



215 



Si)ikclcts 3-5 llowiMcd, as in wheat. 

(iliiinos H.5-9 inm. loiiK ; 2.2-2.'] nun. wide; ohlouK, (jvalc, pnhi'sci-nl, nuin- 
branacoDus. oiliato. kcok-d apex to base; beak .5(>-.75 mm.; sboukicr 
rounded; nerves, abont 5. Simikir to tlie artificial wbeat-ryc liybrid 
except hardly so lar^e, of a more ()1)k)n>.; shape, and of slightly softer 
texture. 

Lennnas as descril)e(l for artilieial wheat-rye hybrid. 

Summary. 

Conccrniiii;- all the heads here shown, it is evident from the ob- 
servations made that all the supposed hybrids are sterile with the 
exception of one seed produced by hybrid No. i, and that the 
peduncles of all are hairy and roughened for a short distance below 
the heads. The artificial hybrid and the one from Tennessee have 
pubescent glumes and lemmas ; the others, nearly smooth glumes and 
lemmas. Pubescence on the glumes and lemmas is dominant in the 
first generation over the glabrous condition, so this character in the 
hybrid depends on the character of the wheat parent in this regard, 
since rye does not have pubescent floral coverings. We know that 
the wheat parent of the artificial hybrid had pubescent floral cover- 
ings, and we may also conclude that the Tennessee head must have 
had a wheat parent wath this character. The hybrids found at 
Arlington were growing in plats of wheats having no pubescence on 
the floral coverings, and therefore are nearly glabrous, as we should 
expect crosses on these wheats to be. 

The larger number of spikelets on the heads than on those of the 
surrounding wdieat is again evidence of rye relationship. The 
greater length of the heads and culms also points to the same 
conclusion. 

The shape of glumes and lemmas, the ciliate keel of the glumes, 
the possession of many nerves, are all similar to the known hybrid 
of wheat and rye. 

The heads of the hybrids from different sources differ somew^hat 
from each other, but this can be shown to be due to differences in 
parentage. The characters of the wheat and rye parents are in- 
herited in the hybrids in the same way as the characters of two 
different wheats would be inherited in their hybrid. 

That the hybrids found were produced by the fertilization of w^heat 
flowers with rye pollen is concluded for these reasons : (i) The plants 
w^ere found growing in plats of w^heat ; (2) no seed has ever been 
secured by any plant breeder, so far as reported, by fertilizing rye 
flowers w4th wheat pollen. In the waiter's ow^n experience no less 
than 80 rye flowers have been pollinated wath the pollen from several 



2l6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

different kinds of wheat and no seed has ever been secured. The 
reciprocal cross is, however, not readily secured. In the writer's 
experience again no less than 173 flowers of different kinds of wheat 
have been pollinated with rye pollen and only 4 seeds have been 
secured, these being in a single head. 

Taking all these things into consideration, it seems evident that the 
plants found are first generation hybrids of wheat and rye, the seeds 
from which they grew having been produced by the natural fertiliza- 
tion of wheat flowers with rye pollen. In no other way can the 
facts be explained. 



THE EFFECT OF GRINDING THE SOIL ON ITS REACTION AS 
DETERMINED BY THE VEITCH METHOD.^ 

P. E. Brown and H. W. Johnson, 
Iowa State College, Ames, Iowa. 

Introduction. 

In the course of some recent studies of Iowa soils, it became neces- 
sary to ascertain their reaction or need of lime. Inasmuch as 
previous tests had been carried out by the Veitch method and com- 
parisons had indicated it to be quite satisfactory, it was decided to use 
that method in this work. 

It was soon noted, however, that the results which were being 
secured were in most cases the direct opposite of those obtained by 
previous tests of samples of the same soil types taken from approxi- 
mately the same localities. For instance, practically all the samples 
from Bremer County were found to be basic in reaction, whereas 
previous tests of the soils of that county had shown that almost all 
were acid. The test had been carried out in exactly the same way 
in both cases. Every step in the operation and every detail in manip- 
ulation were carefully checked but no difficulties were encountered 
with the method. The soil samples were taken in the same way, 
and both lots were chosen as representative of soil types. Further- 
more, they were taken by the same man, so that there was every 
reason to expect that the reaction of the samples would be very 
similar. At least it was felt that the same tendency of the soils to 

1 Contribution from the Laboratory of Soil Chemistry and Bacteriology, 
Iowa Agricultural Experiment Station. Received for publication June 9, 19*15. 



nuowN AND joHNsoN: i:i-|-i:('r of ckindinc 'riii-. son.. 217 



read acid or hasio should have hccn ohscrvcd with l)()lh lots of 
samples. 

There was only one dilTerenee in the two lots of samples. The 
first was secured especially for acidity tests and the soils were tested 
in an unj^^round condition, while the second lot was obtained in con- 
nection with the soil survey of the county and the samples were 
finely ground before being tested. This grinding was necessary in 
order to prepare the samples for the chemical analysis which was 
to be made. It seemed possible, therefore, that the dififerencc indi- 
cated in the reaction of the two lots of samples might be due to the 
grinding. 

As the Veitch method determines the lime requirement or " ap- 
parent " acidity of soils and this is largely dependent on the phenom- 
enon of absorption, it ordinarily would be assumed that grinding 
a soil W'Ould increase its " apparent " acidity because of the greater 
surface exposed. On the other hand, investigations^ have shown 
that many of the common minerals, particularly the zeolites and 
feldspars, wdien reduced to fine pow^der and treated with, carbon- 
dioxid-free water give a more or less strong reaction with phe- 
nolphthalein. Furthermore, in a critical study of the method which 
he devised, Veitch^ noted a development of basicity in tests which 
w^ere allowed to stand longer than sixteen hours and he suggested 
that this might be due to the solution and hydrolyzation of neutral 
compounds present in the soil. 

The following questions then arise : When soils are ground before 
being tested by the Veitch method is their lime requirement greater 
or less than it would be under natural field conditions? Is the ab- 
sorption of the added lime-water increased sufficiently to make the 
" apparent " acidity of the soils greater or will the greater solution of 
minerals lead to a decrease in the acidity indicated by the test ? And 
finally, should soils in a ground condition be tested by the Veitch 
method? Although the above questions are all of considerable in- 
terest scientifically it is with the latter that we are mainly concerned 
at this time. 

As far as the authors are aware it has not been specified in any 
previous work in which the Veitch method was used whether the 
soil should be ground or unground when tested and it is believed 
therefore that the work reported here may.be of value in caUing 
attention to a possible source of error in the manipulation of the 

2 Cameron, F. K., and Bell, J. M., The Mineral Constituents of the Soil Solu- 
tion, U. S. Dept. Agr., Bureau of Soils Bui. No. 30, 1905. 

3 Veitch, F. P., Jour. Amer. Chem. Soc, Vol. 26, No. 6, p. 637. 



2l8 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



test if the condition in which the soil is tested is not distinctly 
specified. 

Experimental. 

In order to determine definitely whether grinding occasions a de- 
crease in the " apparent " acidity of soils, four samples of soil from 
Bremer County were secured and each sample was thoroughly mixed 
and divided into four portions. The first portion was unground and 
unsieved, the second was put through a 20-mesh sieve, the third 
through a 40-mesh sieve and the fourth portion was ground to pass 
an 80-mesh sieve. They were then tested by the Veitch method. 
The results are given in Table i. 



Table i. — Effect of Grinding Sandy Loam Soils on "Apparent Acidity" as 
Determined by the Veitch Method. 



Soil. 
No. 



Soil Type. 



Condition of Soil When Tested. 



Reaction. 



Limestone 
Requirement; 
Pounds per 
2,000,000 
Pounds of 
Silrface Soil. 



14 



51 



57 



24 



Bremer fine sandy loam 



Bremer coarse sandy loam 



Bremer sandy loam 



Carrington sandy loam . 



Unground and unsieved 
Through 20-mesh sieve^ 
Through 40-mesh sieve 
Through 80-mesh sieve 
Unground and unsieved 
Through 20-mesh sieve^ 
Through 40-mesh sieve 
Through 80-mesh sieve 
Unground and unsieved 
Through 20-mesh sieve^ 
Through 40-mesh sieve 
Through 80-mesh sieve 
Unground and unsieved 
Through 20-mesh sieve^ 
Through 40-mesh sieve 
Through 80-mesh sieve 



Acid 

Acid 

Acid 

Basic 

Acid 

Acid 

Basic 

Basic 

Acid 

Acid 

Basic 

Basic 

Acid 

Acid 

Basic 

Basic 



2,816 
2,816 
2,116 



3.520 
3.520 



5.280 
3.168 



3.168 
1,760 



1 Very little grinding. 

2 Considerable grinding. 



All the soils showed acidity when tested in an unground condition 
(Table i) and all showed a basic reaction when they were ground and 
put through an 8o-mesh sieve before being tested. With 3 of these 
samples enough basicity was developed when the soils were ground 
to pass the 40-mesh sieve to change the reaction from acid to basic. 
Even the slight grinding necessary to put the soils through the 20- 
mesh sieve reduced the lime requirements of 2 of the soils. These 
results indicate clearly that grinding increases the basicity of soils 
and those normally having an acid reaction by the Veitch test mav 
show a basic reaction. 



BROWN AND JOHNSON: I'.K FIX r ()!• < , K 1 .\ I • I .\ ( , I 1 1 I'. SOIL. 2 \ <J 



In order to test tlu- point fnrtluM- and .'d.so to iLsccrtain lo what 
extent the sand aiTccts the development of a hasie reaction when a 
ground sample is tested, 5 sami)les of tlie Lintonia series of soils 
from Muscatine County, Iowa, carrying dilTerent contents of sand 
and all reacting acid in the natm-al condition were tested in the same 
wav as the previous soils. The results a])pear in 'J'ahle j. 



Table 2. — Effect of Grinding Sand and Sandy Loam Soils of the Lintonia 
Scries on "Apparent Acidity" as Determined by the Veitch Method. 



Soil 
No. 


Soil Type. 


Percent- 
age of 
Sand. 


Condition of Soil When 
I'ostod. 


Reac- 
tion. 


Limestone Re- 
quirement ; 
Pounds per 
2,000,000 Pounds 
of Surface Soil. 


32 


Lintonia coarse sand 


92.2 


Unground and unsieved 
Through 20-mesh sieve' 
Through 40-mesh sieve 
Through 8o-mesh sieve 
Unground and unsieved 
Through 20-mesh sieve^ 
Through 40-mesh sieve 
Through 80-mesh sieve 
Unground and unsieved 
Through 20-mesh sieve^ 
Through 40-mesh sieve 
Through 80-mesh sieve 
LTnground and unsieved 
Through 20-mesh sieve^ 
Through 40-mesh sieve 
Through 80-mesh sieve 
Unground and unsieved 
Through 20-mesh sieve 
Through 40-mesh sieve- 
Through 80-mesh sieve 


Acid 
Acid 


5,280.0 
4,224.0 








Basic 








Basic 




37 


Lintonia fine sand 


92.0 


Acid 


3.345-0 
3.010.5 
1.672.5 
1.338.0 
2.341-5 
2.341-5 
1.672.5 




Acid 








Acid 








Acid 


18 




91. 1 


Acid 




Acid 








Acid 








Basic 


8 


Lintonia coarse sandy loam 


86.2 


Acid 
Acid 


3.010.5 
3.010.5 
1.338.0 
1.338.0 
5.017.5 
5.017.5 
5.017-5 
4.348.5 









Acid 








Acid 


42 


Lintonia fine sandy loam . 


79.2 


Acid 
Acid 








Acid 








Acid 









1 Little grinding. 

- Ver}' little grinding. 

2 No grinding. 



The coarse sand needed a Httle grinding to put it through the 
20-me3h sieve. This reduced the hme requirement somewhat, but 
when ground and put through the 40-mesh sieve the reaction became 
basic. Very Httle grinding was required to put the fine sand through 
the 20-mesh sieve and while more was required for it to pass the 40- 
mesh and 80-mesh sieves the grinding was not sufficient to make 
the reaction basic. A gradual reduction in the lime requirement of 
the variously treated samples, however, was noted. 

The Lintonia sand required no grinding to put it through the 20- 
mesh sieve and very httle for the 40-mesh. The Hme requirement 
became less where the soil was put through the 40-mesh sieve and the 
reaction became basic when the 80-mesh sieve w^as used. With 



220 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

both the coarse sandy loam and the fine sandy loam, the lime re- 
quirement was changed by grinding, but the soils still tested acid even 
when ground to pass the 8o-mesh sieve. As might be expected, the 
reduction of lime requirement was noted sooner in the coarse sandy 
loam, very little grinding being necessary to put the fine sandy loam 
through the 40-mesh sieve. 

According to these results there seems to be a direct relationship 
between the sand content of the soil and the effect which grinding 
the sample exerts on the reaction by the Veitch test. The larger the 
amount of sand present and the coarser the condition in which it 
exists, the less grinding is required to alter the reaction of the soil 
according to the Veitch test. Where the percentage of sand is low 
the effects of grinding are small, although the influence in reducing 
the lime requirement of acid soils is still noticeable. 

Evidently when soils are ground there is a decrease in " apparent 
acidity due to the solution of minerals and this more than offsets any 
increase in acidity due to greater absorption. In order to test soils 
for their reaction by the Veitch method it is obviously necessary, 
therefore, that the soil be in its natural condition and unground. 

Summary. 

The results of these tests lead to the following conclusions: 

1. When acid soils are ground before being tested by the Veitch 
method the acidity is reduced and frequently the reaction becomes 
basic. 

2. The development of basicity increases with the grinding of the 
soil. 

3. The increase in basicity is greater the greater the percentage 
of sand and it is greater in coarse sandy soils than in fine sands. 

4. To determine the reaction of soils by the Veitch method, they 
should not be ground. 




DAVIDSON: i:ffi-.(T of cumakin and vaniij.in on VVIII.Ar. 221 



A COMPARATIVE STUDY OF THE EFFECT OF CUMARIN AND 
VANILLIN ON WHEAT GROWN IN SOIL, SAND, AND 
WATER CULTURES. 

Jfiiiel Davidson, 
CoRNKLL University, Ithaca, N. Y. 

{Continued from the Jnly-zlugiist number.) 

Experimental Data. 
Object of the Experiments. 

All the laboratory work on soil toxicity dealing with introduced 
organic deleterious substances has been carried out in water cultures. 
No attempts have ever been made to determine how the toxic sub- 
stances which either have been isolated or which have been thought 
possibly to be present in the soil would behave in actual field tests, 
although it could reasonably be expected that the soil through its 
many various agencies would greatly modify their toxic action. 

In the experiments conducted by the writer during the winter of 
1912-13, the principal object was to obtain some data as to how 
substances which were found to be toxic to plants in water cultures 
would affect crops grown to maturity in soil, and how these effects 
would be modified by lime, by each individual mineral fertilizer, and 
by a complete fertilizer. The work was limited to two organic, 
toxins, cumarin and vanillin. These substances were selected because 
they have been used in a number of experiments with water cultures 
in order to demonstrate the behavior of organic toxins, and because 
they could be easily obtained in sufficient quantities in a pure state. 

Experiments with water cultures and quartz cultures were con- 
ducted parallel with the field experiments. 

Experiments with Soil. 

The experiments with soil were conducted in 3-gallon pots in the 
greenhouse. The soil used was Dunkirk clay loam from the ex- 
perimental plots of the Cornell University Agricultural Experiment 
Station. Ten kilograms of soil were weighed out in each pot. The 
pots were watered as frequently as was necessary, once a week at 
the beginning of the experiment when there was very little trans- 
piration and two to three times a week toward the period of maturity. 

27 Since this paper was prepared, a bulletin by Schreiner and Skinner (Harm- 
ful Effects of Aldehydes in Soils, U. S. Dept. Agr. Bui. No. 108, 1914) has 
appeared which gives the results of field plat tests with toxic substances. 



222 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

Only distilled water was used. The moisture content of the soil at 
the time of w^aterin^ was 30 percent on the dry basis. The pots 
were kept under a mulch of white quartz sand. Thirty-six wheat 
seeds were sown in each pot, the stand afterward being thinned to 
12 plants per pot. 

The toxins were added in parts per million and were figured on the 
basis of the highest total moisture content of the soil at the time of 
watering. The concentrations used were 200, 100, and 10 parts per 
milHon for cuniarin, and 1,000, 500 and 10 parts per milUon for 
vanillin. The highest concentrations used were twice the killing 
concentrations in water cultures. 

The experiments consisted of six series: (i) Without additional 
treatment, (2) with Hme, (3) with nitrogen, (4) with phosphoric 
acid, (5) with potash and (6) with a complete fertilizer. Nitrogen 
was added as sodium nitrate, phosphoric acid as disodium phosphate, 
potassium as potassium chloride and lime as calcium hydroxide. 
Nitrogen, phosphoric acid and lime were added on the basis of 400 
pounds per acre, and potassium on the basis of 200 pounds per acre. 
Only chemically pure materials were used. Each series consisted 
of fourteen pots, two for each concentration of the toxins used and 
two control pots. In the tables which follow, the figures reported 
are the averages from the duplicate pots in each case. 

The toxins, the fertilizers and the Hme were added in the dis- 
solved state only. The lime was added as lime water which had 
been titrated against a standard acid. The addition of toxins was 
'repeated three times, each time to the extent of a full equivalent of 
the total moisture. 

Effect on Germination. 

About three weeks after planting, new seedlings ceased to appear 
above ground. Before thinning, the seedlings were counted in order 
to see whether the different treatments had any effect on the ger- 
minating power of the seeds. The percentages of germination and 
the relative germination as compared with the germination in the 
control pots in each series are given in Table 2. 

The only conclusion which would seem to be justified from this 
table is that none of the different treatments had any eft'ect on 
germination. The percentages are very irregular, the differences 
between the dupHcates being larger than between the individual treat- 
ments. The variations seem to be mere fluctuations and seem to 
be due to general conditions affecting germination, as heredity and 
general environmental factors, and not to any single factor arising 
from a particular treatment. 



i)A\ii)S()N : i:i-i'i-xr ov cum.vkin and \' a \ ii.i-i n' on vviii:at. 223 

Tahi.k 2. — Effect of Different Coiui-ntratioiis of i uiiinrin and I'atiUlin on the 
Germination of Wheat, as Shown by the Pereenla</e of iiermination 
and the Ratio of Each to the Control. 



Toxin. 





No 'I'rent- 


CaO. 








KoO. 


Complete 


P.p.m. 


ment. 


















Fertilizer. 


i 


Ratio. 




•Ratio. 


f> 


Ratio. 




Ratio. 




Ratio. 


i 


Ratio. 


200 


53 


76.8 


67 


80.7 


81 


H7.4 


64 


79 


69 


107.8 


69 


88.5 


100 


64 


92.8 


86 


103.6 


78 


113 


81 


100 


V 


104.7 


69 


88.5 


10 


75 


109 


75 


90.4 


75 


108.7 


67 


82.7 


69 


107.8 


75 


96.2 




69 


100 


83 


100 


69 


100 


81 


100 


64 


100 


78 


100 


1,000 


67 


97.1 


83 


100 


69 


100 


72 


88.9 


75 


117.2 


86 


no. 3 


500 


61 


88.4 


83 


100 


72 


104.3 


72 


88.9 


75 


117. 2 


78 


100 


10 


75 


109 


72 


86.7 


67 


97-1 


78 


96.3 


78 


121. 9 


8x 


103.8 



Effect on Yield. 

The plants in the pots were grown to maturity. Observations 
taken during the period of growth did not lead to any definite con- 
clusions. It seemed from time to time that the stand in the cumarin 
pots of the two higher concentrations was inferior to that of the 
control pots in some of the series, especially in the nonfertilized and 
in the limed series. However, no abnormalities in the appearance of 
the plants in these pots were observed. They looked normally green 
and as healthy as the plants in the other pots. 

In Table 3 the weights of the water-free substance for the grain 
and straw and the total yield are given. The table gives the average 
weights for the duplicates and the proportional values of the averages 
with reference to the control pots in each series, the yields of which 
are taken as 100. 

In the weights of the grain shown in Table 3 there is a cer- 
tain regularity in the nonfertilized and in the limed series. The 
highest concentrations give inferior yields ; the lower concentrations 
give yields either equal to or slightly higher than the control pots. 
In the nitrogen series the regularity is preserved with reference to 
the cumarin pots, while in the vanillin pots the yields are arranged 
in the reverse order, the differences, however, being very small. The 
phosphoric acid series preserves the regularity except for the pots 
which received the highest concentration of vanillin. These latter 
gave an abnormally high yield as compared with the remaining pots 
of the same series. The potassium series varies very little and not in 
the expected direction. The complete fertilizer series is very regular, 
the variations being gradual and pronounced as in the first two series. 

The weights of the straw are on the whole less regular than those 
of the grain. The nonfertilized series follows the regular order 



224 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

completely. The limed series also varies in the expected direction 
except in the case of the second concentration of cumarin. The 
remaining series do not show any regularity in their variations. 

Table 3. — Weights {Water-free Substance) of Grain, Straw and Total Weight 
Obtained from Pot Cultures of Wheat Variously Fertilized and Treated 
with Different Concentrations of Cumarin and Vanillin, with 
the Ratio of Each to the Control Taken as 100. 
Weights of Grain. 







No Treat- 
ment. 


CaO. 


N. 


P2O5. 


K2O. 


Complete 
Fertilizer. 


Toxin. 


P.p.m. 












. 










X. 








!> 


.2 

P< 


.be 




be 


.2 


.bo 


.0 


.hp 

"v 
> 


.0 


> 


.0 

<X 






Gm. 




Gm. 




Gm. 




Gm. 




Gm. 




Gm. 




Cumarin . . 


200 


4.21 


64.8 


6.12 


74-5 


14.9 


85.1 


4.96 


80.5 


6-34 


100.8 


10.9 


63 




100 


5.08 


78 I 


7-55 


92.0 


18.3 


104.6 


6.42 


104.2 


6.61 


105. 1 


13.8 


70 8 




10 


6.75 


103.9 


7.69 


93-7 


18.9 


108 


7.16 


116. 2 


6.58 


104.6 


16.3 


94-2 


Control, , . 




6.50 
5-79 


100 


8.21 


100 


17-5 
16.8 


100 


6.16 


100 


6.29 
6.93 


100 


17-3 
15-2 


100 


\T •II' 

Vanillin . . . 


1 ,000 


89.1 


5-66 


68.9 


96 


9.96 


161 


110. 2 


87.9 




500 


6.72 


103.4 


6.48 


78.9 


16.3 


93-1 


6.14 


99-7 


6.37 


101.3 


15 


86.7 




10 


7-47 


1 14.9 


8.28 


100.9 


16.1 


92 . 


6.55 


106.3 


6.58 


104.6 


15-6 


90.2 










Weights of 


Straw. 












Cumarin . . 


200 


23-4 


85.4 


25-9 


92.5 


54-7 


102 


25-7 


101.6 


22.4 


104.7 


40.0 


95-2 




100 


25-9 


94-5 


29-5 


105-3 


55-7 


103.9 


27.6 


109. 1 


21. 1 


98.6 


45-9 


109.3 




10 


28 


102.2 


27-5 


98.2 


53-2 


99-3 


27.4 


108.3 


24-5 


114-5 


44-7 


106.4 


Control 




27.4 
24.6 


100 


28 


100 


53.6 
48.9 


100 


25-3 
34.8 


100 


21.4 
24.9 


100 


42 
43-9 


100 


Vanillin . . . 


1,000 


89.8 


22.9 


81.8 


91.2 


137-6 


116. 4 


104.5 




500 


27.1 


98.9 


24.7 


88.2 


50.3 


93.8 


24.2 


95-6 


20.3 


94-9 


47-5 


113. 1 




10 


28 


102.2 


28.5 


101.8 


52.5 


97.9 


23.2 


91.7 


19 


88.8 


46-4 


no. 5 










Total 


Weights. 














Cumarin. . 


200 


27.6 


81.4 


32.1 


88.6' 69.7 


96.7 


30.7 


97-4 


28.7 


103.6 


50.8 


85.8 




100 


31 


91.4 


37-1 


102.5 


74-1 


102.8 


34 


107.9 


28.7 


103.6 


54-8 


92.2 




10 


34-8 


102.7 


35-2 


97.2 


72.1 


100 


34-5 


109.5 


31. 1 


112.3 


61 


102.7 


Control 




33-9 
30.4 


100 


36.2 
28.6 


100 


72.1 
65-7 


100 


3I-S 
44-7 


100 


27-7 
31.8 


100 


59-4 
59-1 


100 


Vanillin . . . 


1,000 


89.7 


79 


91. 1 


141-9 


114.8 


99-5 




500 


33.8 


99-7 


31.2 


86.2 


66.6 


92.4 


30.4 


96.5 


26.7 


96.4 


62.5 


105.2 




10 


35-4 


104.4 


36.5 


100.8 


68.7 


95-3 


29.7 


94-3 


25-5 


92.1 


62 


104.3 



The total yields of the grain and straw naturally occupy a place 
between the weights of each separately with reference to the ten- 
dency to show a regular trend in any direction. The nonfertilized 
and the Hmed series again prove to be the most regular. The com- 
plete fertilizer series comes next, being quite regular in the cumarin 
pots. The nitrogen series shows a tendency to regularity, being 
more regular in the vanillin half. The potassium series again proved 
to be the least regular. On the whole, the variations in the total 
yield are not very sharp. 



D.W IDSON : lOFFlX r Ol- CTMAUIN AND VANILLIN ON VVIII-AT. 225 

The Liciicral impression i)ro(lucc(l by examination of TabK- 3 
would 1)0 that the highest concentrations of the cmnarin and vanillin 
caused a sh\<;lit depression in yield, especially in the yield of j^n-ain, 
and that the depression is more pronounced and more rej^jular in 
the non fertilized, in the limed, and in the com[)lete fertilizer scries. 
The addition of the individual fertilizers seemed to have a disturbing 
influence on the tendency to follow the regular effects of the toxins 
used. No conclusion can be drawn as to whether it was accidental 
(which is not improbable in view of the fact that the variations in 
general were not very sharp) or whether it was due to the influence 
of the fertilizer. Neither is it possible to draw any conclusions with 
reference to the eft"ects of the individual fertilizers in the absence of 
distinct variations since there was only one series for each fertilizer. 
The complete fertilizer did not seem to modify the effects of the 
cumarin and vanillin. 

Effect on the Nitrogen Content. 

The nitrogen content may serve sometimes as an indication of the 
presence of certain factors which influence the general yield of a 
crop. If a depression in yield is caused by some accidental factor, 
the tendency is in the direction of a relatively higher nitrogen content. 
The reason for this phenomenon might be due either to the fact 
that the interfering factor does not affect the production of nitrates 
in the soil, or that it does not affect the assimilative power of the 
plant for nitrogen. It was thought, therefore, that the nitrogen con- 
tent of the crops might throw some light on the nature of the 
influence exerted by the cumarin and vanillin treatment. Table 4 
gives the percentages of nitrogen in the grain and in the straw and 
the ratios of the different treatments to the control, taking the per- 
centage of nitrogen in the controls as 100. 

Examining these tables, we find that the percentages of nitrogen 
in the straw fluctuate too irregularly to allow of any generalizations. 
We find, for instance, that in the nonfertilized and the limed series, 
which proved to be the most regular ones with reference to the 
weight of water-free substance the highest concentrations of cumarin 
and vanillin gave approximately the same percentages as the controls. 
In the remaining series, the concentration of 200 parts per million of 
cumarin gave somewhat higher percentages than the controls. The 
other concentrations of cumarin, as well as all the concentrations of 
vanillin, do not follow any regular order. 



226 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 4. — Nitrogen Content of Wheat Grain and of Strazv Grown in Pot 
Cultures Variously Fertilized and Treated with Different Concentrations 
of Vanillin and Cumarin, with the Ratio of Each to 
the Control Taken as 100. 
Wheat Grain. 







No 
m 


Treat- 
ent. 


CaO. 


N. 


P2O6. 


K2O. 


Complete 
Fertilizer. 


Toxin. 


P.p.m. 


Nitrogen. 


.2 

Pi 


Nitrogen. 


Pi 


Nitrogen. 


Pi 


Nitrogen. 


.2 

Pi 


j Nitrogen. 


6 
Pi 


Nitrogen. 


_o' 

Pi 






% 




% 




%■ 




% 




% 




% 




Cumarin . . 


200 


1.72 


107.5 


I.91 


107.9 


2.27 


ii3^5 


2.15 


II4.4 


2.06 


106.7 


2.15 


108.6 




100 


1-75 


109.4 


1.76 


99.4 


2.01 


100.5 


2.00 


106.4 


1.95 


lOI 


2.09 


105^5 




10 


1. 81 


113. 1 


1.58 


89.3 


2.07 


103^5 


1.96 


104.3 


1.89 


97.9 


2.10 


106. 1 


Control . . . 




1.60 


100 


1.77 
1.89 


100 


2.00 


100 


1.88 


100 


1-93 
1.89 


100 


1.98 
2.03 


100 


Vanillin . . . 


1,000 


1.76 


no 


106.8 


1.89 


94-5 


1.97 


104.8 


97-9 


102.5 




500 


1.82 


II3-7 


1.68 


94.9 


2.01 


100.5 


1.98 


105.3 


1-93 


100 


2.06 


104 




10 


1.68 


105 


1. 81 


102.3 


2.04 


102 


1.93 


102.7 


1.97 


102. 1 


2.13 


107.6 


Wheat Straw. 


Cumarin . . 


200 


0.39 


102.6 


0.33 103. 1 


0.46 


135^3 


0.45 


II8.4 


0.39 


114.7 


0.35 


112. 9 




100 


•31 


81.6 


•34 


106.2 


.41 


120.6 


•33 


86.8 


•32 


94.1 


.35 


112. 9 




10 


•31 


81.6 


.38 


118. 8 


.38 


III. 8 


•34 


89.5 


•35 


102.9 


.35 


1 12.9 


Control . . . 




.38 
.42 


100 


.32 
•32 


100 


•34 
•36 


100 


•38 
.36 


100 


•34 
•30 


100 


•31 
.29 


100 


Vanillin. . . 


1,000 


no. 5 


100 


105.9 


94.7 


88.2 


93.6 




500 


.41 


107.9 


.30 


93-7 


.40 


117. 6 


•36 


94-7 


•32 


94.1 


•39 


125.8 




10 


•30 


78.9 


•33 


103. 1 


•43 


126.5 


•39 


102.6 


.37 


108.8 


.42 


135.5 



The percentages of nitrogen in the grain exhibit a regularly borne 
out consistency with reference to the concentration of 200 parts per 
million of cumarin, as they are consistently higher than those of the 
controls in all the series. With reference to the remaining concen- 
trations of cumarin and those of vanillin, the consistency varies with 
the series, and does not, on the whole, allow any generalizations as 
in the case of the straw. 

The depression in yield of grain, which was most pronounced in 
the case of the concentration of 200 parts per million of cumarin, 
would seem to be accompanied by a relatively higher nitrogen con- 
tent which is characteristic of the presence of some factor interfering 
with plant growth. The question is whether the effect of the inter- 
fering factor was directly on the plant, causing some morphological 
derangement or interfering with its physiological functions, or 
whether the effect was on the medium in which it grew. 

The appearance of the plants in the pots to which the toxic sub- 
stance had been added was perfectly normal, as stated above. The 
roots were found to permeate the soil in every direction and did not 
show any inferior development as compared with the controls. The 



DAVIDSON: I'.I'IMUT OF ("UMAKIN AND VANILLIN ON VVIIIIA'I". 22/ 



depression in yield was not exidently dui' to lack of nilro^^en, hut the 
possihility of its heinj^ dne to a relatixe delicicncy in some of the 
other availahle elements of plant food, aetnal or physiological, caused 
hy the interferin<^- factor, is not exclnded. It is also possihle that the 
interferini^ factor affected the ])hysical and hioloi^ical conditions of 
the soil. 

Jiffcct on Nitrates. 
In order to ohtain some idea of the effects of the toxins used on 
the hiological activity of the soil, the soil in the pots was analyzed 
for nitrates. 

The pots could not be handled immediately after the crops were 
harvested, but were held at a low moisture content and were analyzed, 
a complete series at a time, so that each series could be compared only 
with its own control pots. During the sampling, the soil was re- 
moved from the pots, pulverized, and thoroughly mixed. After the 
first sampling, the soil was returned to the pots, kept at about 25 
percent of moisture for a time, and analyzed again. This was 
analogous to incubation, as the pots were kept in the greenhouse 
and were all subject to the same variations in temperature, which 
(the weather at that time of the year being constant) were limited 
only to the difference of the day and night temperature. Again, one 
series was handled at a time, so that each series was incubated for a 
different length of time. 

The nitrates in parts per million are given in Tables 5 and 6. 
In Table 5 the averages of the duplicate pots are compared with the 
averages of the control pots in each series, the latter being taken as 
100. In Table 6 the increase in nitrates for the period of incuba- 
tion was calculated and the average increase of the duplicate pots is 
compared with the average increase of the control pots taken as 100. 

Table 5. — Nitrates in Pot Cultures Variously Fertilized and Treated with Dif- 
ferent Concentrations of Cumarin and Vanillin, as Determined before 
Incubation, with the Ratio of Each to the Control Taken as 100. 



Toxin. 



P.p.m. 



No Treat- 
ment. 



CaO. 



P^O. 



K50. 



Complete 
Fertilizer. 



o = 

CM 



Cumarin 



200 
100 
10 



Control . 

Vanillin . . . i i,ooo 

• ••I 500 

... I 10 



15.6 
14.2 
16 
18.9 
9.4 
II. 2 
15.2 



82.5 

75.1 
84.7 

100 
49-7 
59-3 
80.4 



33- 5 
31.8 
32.3 

34- 5 
19.8 
24.7 
26 



97.1 
92.2 
93-6 
100 
57-4 
71.6 
75-4 



20.1 
22.9 
31.6 
34-8 
23.2 

38.3 
29.9 



57-8 37-3 
65.9 44.8 
90.8 36.5 

100 I 31.3 
66.7, 60.6 

no I 35.6 
85-9 32.5 



119.21 36.6 



I43-I 

116.6 

100 

193.6 

II3-7 

103.8 



36.6 

36.7 

34-5 

31 

33-7 

21.5 



106. 1 
106. ij 
106.4 
100 
89.9 
97-7| 
62.3' 



52.2 
52.8 
51.6 
81.2 
52.2 
43-6 
55-9 



64-3 

65 

63.5 

100 

64.3 

53-7 

68.8 



2 28 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 6. — Increase of Nitrates after Incubation from Pot Cultures Variously 
Fertilized and Treated with Different Concentrations of Cumarin and 
Vanillin, with the Ratio to the Control Taken as lOO. 







No Treat- 
ment. 


CaO. 


N. 


P2O0. 


K2O. 


Comp. 
Fert. 


Toxin. 


P.p.m. 


Incr., 
P.p.m. 


Ratio. 


Incr., 
P.p.m. 


Ratio. 


Incr., 
P.p.m. 


Ratio. 


Incr., 
P.p.m. 


Ratio, 


Incr., 
P.p.m. 


Ratio. 


Incr., 
P.p.m. 


Cumarin. . 


200 


42.9 


129.6 


23.9 


85-4 


21.6 


73 


29.9 


198 


14.6 


69.2 


17.4 




100 


41.7 


126 


23-5 


83.9 


26.4 


89.2 


31 


208.3 


9.5 


48.1 


9.9 




10 


34-3 


103.6 


27-5 


98.2 


33-7 


113. 8 


29.7 


196.7 


21.5 


IOI.9 


16.3 


Control. 




33-1 
24-3 


100 


28 


100 


29.6 
31-9 


100 


I5-I 
27-5 


100 


21. 1 


100 


Loss 


Vanillin. . . 


1,000 


73-4 


19-5 


69.6 


107.8 


182. 1 


14.9 


70.6 


14-3 




500 


28.2 


84.6 


19.1 


68.2 


22.2 


75 


23.4 




II. 2 


53-1 


15-5 




10 


51-7 


156.2 


24.6 


87.9 


26.5 


89.5 


22.9 


151-6 


9.9 


46.9 


25-4' 



As is seen in Table 5, the nitrates in four series are consistently 
higher in the control pots than in the pots to which the toxins had 
been added. The phosphoric acid series goes in the opposite direc- 
tion and the potassium series is only partially consistent. 

Table 6, presenting the data for the incubation period, shows that 
in the toxin-treated pots* of the lime, the nitrogen, and the potassium 
series the increase in nitrates is lower than in the control pots. The 
phosphoric acid goes the other way as in the period preceding in- 
cubation. In the complete fertilizer series, the control pots showed 
a reduction in nitrates instead of an increase, so that there is no 
standard of comparison. In the nonfertilized series, the increase in 
the control pots was larger than in the vanillin pots, but smaller than 
in the cumarin pots. This might have been due to the fact that this 
series was incubated for the longest period of time and the cumarin 
was completely decomposed. As will be seen later, there are indi- 
cations that the effects of cumarin are more subject to amendment 
through decomposition by the soil agencies than are the effects of 
vaniUin. 

The general impression produced by the figures representing the 
results of the analysis for nitrates, would be that the addition of the 
toxins used seemed to interfere with nitrification. 

The behavior of the cumarin and the vanillin with reference to 
their effects on nitrification would seem to be analogous to the 
behavior of soluble organic matter in general. Konig, Hasenbaumer 
and Glenk^^ found that the addition of glucose invariably inhibited 
nitrification. The inhibiting effect of soluble organic matter on 

28 Konig, J., Hasenbaumer, J., and Glenk. K., Uber die Anwedung der Dya- 
lise, etc., Landw. Vers. Stat., 79-80 (1913), P- 491-534- 



DAVIDSON: i:i-i'i:( r oi' (Tmaumx and \ anii.i.i\ on wiii:a'I'. 229 

nitrification nii<;lu he cither (hrcctiy on the nitrifying;- or«;anisin or on 
the soil factors alVcctin<;- their activity. Anotlier ])ossihility is that 
the sohihle ors^anic matter stininlates the .growth of other hacteria 
which compete with the nitrifyini^ orji^anisms for the means of snh- 
sistence. K(")nii^^ and his associates invariahly fonnd higher hactcrial 
nnmhers as a resnU of the achhtion of i^lucosc. 

liffcct Couducth'ity. 

The same anthors found that the adcHtion of <^lncosc reduced the 
conductivity of the soil. The explanation sui2^j2^csted hy them is that 
the glucose acts protectively toward the electrolytes of the soil, thus 
interfering with the movements of the ions. In discussing the de- 
pression in yield, which under certain conditions is produced by the 
addition of sugar, the authors suggest that the electrical conductivity 
or the movement of the ions is in itself a factor in soil fertility. It 
was, therefore, interesting to see how the cumarin and vanillin, 
which produced a slight depression in yield practically similar to that 
produced by the addition of glucose, would affect the conductivity 
of the soil in the experimental pots. 

Fifty grams of soil were thoroughly mixed with 50 percent of 
distilled water on the dry basis, and the resistance measured by a 
Wheatstone bridge. Tables 7 and 8 show the resistance in ohms 
calculated at 60° F. before and after incubation. 

The results are not entirely consistent, but nevertheless a general 
inspection of the tables gives the impression that the soil in the pots 
to which cumarin and vanillin had been added showed a somewhat 
higher conductivity as compared with the control pots, for the period 
following incubation. 

Table 7. — Effect on Conductivity of Various Fertilizers and Treatments with 
Different Concentrations of Cumarin and Vanillin, as Shown hy the 
Resistance in Ohms Calculated at 60° F. before Incubation, 
with the Ratio of Each to the Control. 



Toxin. 


E 


No Treat- 
ment. 


CaO. 


N. 


P205. 


K20. 


Complete 
Fertilizer, 




Resist- 
ance. 


Ratio. 


Resist- 
ance. 


Ratio. 


Resist- 
ance. 


Ratio. 


Resist- 
ance. 


Ratio. 


Resist- 
ance. 


Ratio. 


Resist- 
ance. 


Ratio, 


Cumarin 


200 


2,174 


104.2 


1,970 


96.7 


2.137 


112. 7 


1.779 


82.3 


1,609 


115. 2 


1,774 


99-7 




100 


2,229 


106.8 


2,003 


99.6 


2,250 


118. 7 


1,720 


79.6 


1,700 


121. 7 


1,681 


94-5 




10; 2,369 


II3-5 


2,181 


107. 1 


1.996 


105-3 


1. 951 


90.3 


1,701 


121. 8 


1,702 


95-7 


Control . 




2,087 
2,416 


100 


2,038 
2,324 


100 


1,896 
1.875 


100 


2,161 


100 


1,397 

1,579 


100 


1,779 
1,682 


100 


Vanillin 


1,000 


115. 8 


114 


98.9 


1,711 


79.1 


113 


94- S 




500 


2,195 


105.2 


2,446 


120. 1 


1.550 


81.8 


1,981 


91.7 


1,337 


95-7 


1,714 


96.3 




lol 1,979 


94.8 


2,484 


121. 9 


1,675 


88.3 


1,951 


90.3 


i,944|i39.i 


1,423 


80 



230 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 8. — Effect on Conductivity of Various Fertilisers mid Treatments with 
Different Concentrations of Cumarin and Vanillin, as Shown by the 
Resistance in Ohms after Incubation Calculated at 60° F., 
with the Ratio of Each to the Control. 



Toxin. 


g 


No Treat- 
ment. 


CaO. 


N. 


P205. 


K2O. 


Complete 
Fertilizer. 




Resist-' . 
ance. Ratio. 


Resist- 
ance. 


Ratio 


Resist- 
ance. 


Ratio. 


Resist- 
ance. 


Ratio. 


Resist- 
ance. 


Ratio. 


Resist- 
ance. 


Ratio. 


Cumarin 


200 


1,680 90 


1. 515 


93-2 


1.550 


110 


1.499 


86.8 


1.356 


102 


1,642 


103.2 




100 


1,867 100 


1,580 


97 


1,700 


120 


1.430 


82.8 


1.455 


109 


1,488 


93-5 




10 


1,929 103 


1.633 


105 


1,487 


105 


1.653 


95-7 


1,381 


103.8 


1.540 


96.8 


Control , 




1,867 100 

1.736 93 


1,625 
1,817 


100 


1,412 
1,475 


100 


1,727 
1.430 


100 


1.330 
1.307 


100 


1. 591 
1.540 


100 


Vanillin 


1,000 


112 


104.5 


82.8 


98.3 


96.8 




500 


1.744' 95 


1,732,107 


1.525 


108 


1,628 


94-3 


1.233 


92.7 


1.565 


98.4 




10 


1.649 88.3 


1,694 104 


1,600 


113 


1,801 


104.3 


1.529 


115 


1,283 


80.6 



This, however, is not directly contradictory to the results ob- 
tained by Konig and his associates, since we have introduced the 
crop factor, while their results were obtained without growing any 
crop in the soil experimented with, and since the measurements in 
these experiments were made a comparatively much longer time 
after the organic substances were added. 

The soil in the cumarin and the vanillin pots seemed to show after 
incubation a higher conductivity in spite of the fact that the re- 
spective treatments apparently reduced their nitrate content. It is 
possible that the plants withdrew from the soil, in the presence of 
the toxins used, less of the other electrolytes. This might have been 
due either to the fact that the toxins interfered directly with the 
absorption of these electrolytes by the plant, or that they stimulated 
the growth of microorganisms which held the electrolytes tied up in 
their tissues at the time of active plant growth. 

That organic substances which prove to be toxic to higher plants in 
water cultures may be favorable to the growth of microorganisms, 
was shown by the fact that a solution containing 200 parts per million 
of cumarin showed to the naked eye an abundant growth of molds 
and fungi when allowed to stand for some time. The same was true 
with dihydroxystearic acid which had been isolated from a soil 
in Tompkins County, New York. 

It is remarkable that Konig and his associates failed to see the 
possibiUty of any connection between the higher bacterial numbers 
resulting from the addition of sugar and the other phenomena result- 
ing from the same treatment, as depression in yield, lowering of 
conductivity, and the reduction in the nitrate content. Such a con- 



D.w iDsoN : Ki:c r oi- cumauin and vanillin on wiii:Ar. 231 



noction would not \)v im|)rol)al)K' accordin.L^' to tlu' works of Stoklasa,-" 
Scvoriir'" aiul Dusclu'lschkin.''' 

KXI'KRIMKN IS WITH WaTKU CuI.TUKKS. 

Rfjcct on (icnninatioii. 
Wheat seeds were allowed to i^erniinate on Idter i)aj)er in ])etri 
dishes. Fifty seeds were ])lace(l in each dish to which 15 c.c. of 
solutions of the respective concentrations of cuiuarin and vanillin 
were added. Fifteen c.c. of distilled water were added to the control 
petri dishes. The test was run in duplicate. Ohscrvations were 
taken after six and ten days. Tahle 9 shows the results obtained 
after six days. 



Table 9. — Effect of Different Concentrations of Cumarin and Vanillin on the 
Germination of Wheat in Water Cultures. 



Toxin. 


P.p.m. 


Average 
Germina- 
tion. 


Percent. 


Description of Seedlings. 


Cumarin .... 
Control 


200 
100 
10 








Normally developed seedlings. 
Better than in the previous case. 
Very weak. 

Better than in previous case. Some poor, 

but normal seedlings. 
Vigorous. 


22 
22 

5 
9 

26 


44 
44 
10 
18 

52 


Vanillin 


1,000 

500 

10 



Most of the seeds w^hich are recorded as not germinated in reahty 
made slight efforts to germinate, but evidently the seedlings were 
killed in the earliest stage of embryonic development. 

The second observations did not reveal any changes with reference 
to the cumarin treatment, except that the seeds were all overgrown 
with molds and fungi. The vanillin petri dishes, however, showed 
considerable improvement, especially those which received 500 parts 
per million. In these the percentage of germination and the per- 
centage of normally developed seedlings increased considerably 
(germination, 32 percent; normally developed seedlings, 26 percent). 

It is thus seen that cumarin had a more injurious effect on ger- 
mination than vanillin. It is also seen that the deleterious effect of 

Stoklasa, Julius, Biochemischer Kreislauf des Phosphat-ions im Boden, 
Centbl. Bakt, 29, (II), 191 1, p. 385-519. 

30 Severin, S. A., Changes of Phosphoric Acid in the Soil, etc., Centbl. Bakt, 
28, (II), 1910, p. 561-580, 

31 Duschetschkin, A., Biological Absorption of Phosphoric Acid, Jour. Exp. 
Agr. (Russia), 12, p. 650-666. 



232 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

the vanillin decreased with the time, in spite of the fact that the 
respective solutions became more concentrated due to evaporation. 

Effect of Ciimarin on the Growth of Seedlings Grown in Nutrient 
Solution of Various Concentrations. 
Tumblers of 250 c.c. capacity were used. They were covered with 
paraffined paper in which small holes were made with a pointed 
glass rod. The roots of germinated seedlings were carefully intro- 
duced into the tumblers filled with nutrient solution, through the 
holes of the paper covers, so that the attached seeds remained rested 
on the upper side of the paper. Four seedlings were planted in each 
tumbler. 

The nutrient solution used was of the following composition : 



Calcium nitrate 2.7 gm. per liter. 

Monopotassium phosphate 1.5 gm. per liter. 

Magnesium sulphate 0.6 gm, per liter. 

Potassium chloride 0.75 gm. per liter. 

Ferric sulphate 0.05 gm. per liter. 



This nutrient solution was used in full strength and also diluted 3 
and 10 times respectively. The concentrations of cumarin w^ere 200, 
100, and 10 parts per million. The experiment was run in triplicate. 
The seedlings were grown for two weeks. The dry weights de- 
termined collectively for each set of triplicates are given in Table 10. 



Table 10. — Dry Weights of Wheat Seedlings Grown for Two Weeks in Dif- 
ferent Concentrations of Cumarin. 



Cumarin. 


Concentration of Nutrient 
Solution. 


Dry Weights. 


Relative Weights. 


p. p.m. 




. Grams. 




200 


I : 10 


Killed after 7 days 


100 


I : 10 






10 


I : 10 


0.2562 


82 


Control 


I : 10 


.3120 


100 


200 


I : 3 


Killed after 7 days 


100 


I : 3 






10 


I : 3 


.5160 


76 


Control 


I : 3 


.6820 


100 


200 


I : I 


Killed after 7 days 


100 


I : I 






10 


I : I 


.4630 


60 


Control 


I : I 


.7696 


100 



As seen from Table lo, the depressing efifect of lo parts per million 
of cumarin is greater in the nutrient solution of the higher concen- 
tration. It is evident, however, that the increased nutrient content 
did not increase the deleterious action of the toxin, since the absolute 
yields are higher in the higher concentrations of the nutrient solu- 



DAVIDSON: KKFF.CT OF CTMAKIN AND VANIIJ.IN ON WIII'.A'I'. 233 



tion. The dololcrious effects of the toxin were more ])ronoiiiu((l in 
the case of the higher concentrations of the nntrient solnlion, j^roh- 
ably because the yields in general were higher witli these con- 
centrations. 

It is clear, however, that the higher concentrations of the nutrient 
did not reduce the toxicity of the cutnariii. The ameliorating effect 
of phosphoric acid on cuniarin reported by Schreiner and Skinner''^ 
is evidently not antagonistic in character, nor is it evidently due to 
the fact that phosphoric acid increases the resisting power of the 
plant to the action of the toxin, since an increased concentration of 
this substance did not have the same effect in a balanced solution. 

It is possible that the results obtained by Schreiner and Skinner 
were due to the residual elfect of the source of phosphoric acid after 
the latter was used. It is also possible that the presence of cumarin 
does not interfere with the absorption of phosphoric acid, while it 
does interfere with the absorption of the other nutrient elements, 
and therefore the difference in yield between the controls and the 
cumarin cultures are more pronounced in the case of distilled water 
and a balanced nutrient solution than in the case of a solution of 
phosphoric acid. 

Effects of Small Quantities of Soil on the Behavior of Cumarin and 

Vanillin. 

The methods used were in the main similar to those in the previous 
experiment. The nutrient solution used was the one given above, 
diluted four times. The experiment was run in triplicate, and con- 
sisted of two series which differed only in the fact that each tumbler 
of the second series received 2 grams of field soil. Both series were 
run simultaneously, and under exactly the same conditions. The 



Table ii. — Dry Weights of Wheat Seedlings Grown for Two Weeks in Water 
Cultures Containing Different Concentrations of Cumarin and Vanillin, 
with and without the Addition of Small Quantities of Soil. 



Toxin. 


Concentration. 


Solution Without Soil. 


Solution Plus 2 Grams of Soil. 


Average Weight. 


Ratio. 


Average Weight. 


Ratio. 


Cumarin 

Control 

Vanillin 


p.p.m. 

200 
100 
10 

1,000 
500 
10 


Grams. 
Killed after 7 days 

0.1473 77 
.1901 100 
Killed after 7 days 

.1817 1 92 


Grams. 
0.1625 
.1708 

.1874 
.1631 
Killed aft 

•1552 


99 
104 

115 

100 

er 7 days 
95 



32 Schreiner, Oswald, and Skinner, J. J., Organic Compounds and Fertilizer 
Action, U. S. Dept. of Agr., Bur. Soils Bui. No. 77. 191 1. 



234 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

seedlings were grown for two weeks. The average weights of the 
water-free substance from the triphcate cultures are given in Table ii. 

As seen from Table ii, the toxic effects of the cumarin were 
completely destroyed by the addition of a very small quantity of soil. 
As the table shows, the cumarin tumblers of the second series gave 
higher yields than the controls, but it is safer to ignore this fact 
since we can not base too much on small differences in yields obtained 
from seedlings grown for two weeks. It is clear, however, that the 
toxic effects of the cumarin were entirely overcome. This was also 
shown by the appearance of the seedlings, especially by the appear- 
ance of the roots, which were perfectly healthy and very much 
branched in the concentration of 200 parts per million of cumarin. 
The comparison with the similarly treated cultures which had not 
received any soil is so striking that the ameliorating effect of the 
soil on the action of cumarin under the conditions of this experiment 
is beyond any doubt. On the behavior of the seedlings in the vanillin 
solutions, on the other hand, the addition of soil did not have any 
effect whatsoever. 

The effect produced by the soil in the case of cumarin was prob- 
ably due not to adsorption, since the quantity of soil was so small, 
but to decomposition. The difference in the effects of the soil 
on cumarin and vanillin may be due either to the fact that vanillin 
is not as readily decomposed by the soil organisms as cumarin, or to 
the fact that the products of decomposition of vanillin are just as 
toxic as vanillin itself, while the decomposition products of cumarin 
are not toxic. 

This experiment would suggest that the depressing effect of 
cumarin on the yields in the experiments with soil might be due to 
different causes than those operative in water cultures. 

Experiment with Quartz Cultures. 
The experiment was carried out in half-gallon pots. White quartz 
sand thoroughly washed with hydrochloric acid was used. Two 
kilograms of quartz were used per pot. The nutrient solution given 
above in which enough cumarin and vanillin were dissolved to make 
up the usual respective concentrations, was added to each pot to the 
extent of 25 percent of the weight of the quartz. The pots were 
kept at 25 percent of moisture, and were watered with distilled water. 
Nutrient solution was added from time to time. The addition of 
the toxins when repeated was in solutions of the respective concen- 
trations and in equivalents of the total moisture. Sixteen wheat 
seeds were planted in each pot. The germinated seedlings were 
thinned out to 5 per pot. The experiment was run in duplicate. 



DAVIDSON: Kl-FJCCT OK CU.MAUIX AND VANILLIN ON WIIKAT. 235 



Effects on (u'niiiiiiilioii. 
After the seedlings ceased to appear above ,L;roun(l, they were 
counted, and the i)erccnla.i>e of germination and tlu- relative values, 
taking: the controls as loo, were calculated, d he results are j^iven in 
Table iJ. 



Taiu.e 12.— Effect of Different Concentrations of Cumarin and I'dnillin on the 
C'enniiiation of Wheat in Quarts Cultures. 



Toxin. 


Concentratioi.. 


Average 

Germinaiion. 


Percentage, 


Ratio to Con- 
trol. 




p.p.7n. 

200 
100 
lO 


None 
None 
II 

12 

13 

lO 

14 














69 
75 
8i 

62 

87 


92 
100 

loS 
84 
1x6 


Control 


Vanillin 


I.OOO 

500 

10 







As seen from Table 12, cumarin had the same effects on germina- 
tion in quartz as in a liquid medium. The seeds in the pots of the 
two highest concentrations, when dug out, had the same appearance 
as in the petri dishes — slightly swelled and having made a very slight 
effort to germinate. 

Vanillin did not have any effect at all on germination in quartz 
cultures. The higher results than in the control pots as well as 
the lower results obtained in these cultures are to be regarded as mere 
fluctuations. 

Effect on Growth. 
After the thinned-out seedlings had been grown for about seven 
weeks, the tops were harvested and the weights of the water-free 
substance determined. The results are given in Table 13. 



Table 13. — Dry Weights of Wheat Seedlings Grown in Quarts Cultures 
Treated with Different Concentrations of Cumarin and Vanillin. 



Toxin. 


Concentration. 


Number of 
Equivalents 
Added. 


Average 
Weight. 


Ratio to 
Control. 




p. p.m. 




Grams. 




Cumarin 


200 


I 


Did not come up above 








quartz 




100 


I 


Did not come up above 








quartz 




10 


2 


1.6 


94 


Control 






1-7 


100 


Vanillin 


1,000 


3 


1. 25 


74 




500 


3 


1.65 


97 




10 


3 


1.60 


94 



236 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

As seen from Table 13, the cumarin behaved in quartz cultures in 
the same way as in water cultures without the addition of soil. The 
vanillin behaved approximately as in the soil. 

General Discussion. 

Since vanillin behaved the same way in quartz sand with a com- 
paratively low adsorptive power as in a clay soil with a compara- 
tively high adsorptive power, the ameliorating effects of the quartz 
and of the soil on vanillin were probably not due to adsorption. 
Since, however, the soil organisms added to the water cultures with 
the small quantities of soil did not have any effect on the action of 
vanillin, the ameliorating effect of soil and quartz on this toxin was 
probably not due to decomposition. In all probabihty, vanillin is 
only toxic when applied in a liquid medium which envelops the roots 
completely in a continuous layer. This would seem to be borne out 
by the experiment on the effects of cumarin and vanillin on germina- 
tion in a liquid medium ; on longer standing the inhibiting effect of 
vanillin on germination decreased, in spite of the fact that the solu- 
tion became more concentrated, due to evaporation. 

The case is entirely different with reference to cumarin. A small 
quantity of soil added to water cultures containing 200 parts per 
million of cumarin, which is double the killing concentration, com- 
pletely destroyed the injurious effects of this toxin. The distribu- 
tion of the toxic solution in films on the surface of the quartz grains 
did not have any ameliorating effect at all on the action of cumarin. 
Evidently the ameliorating effect of the soil on this toxin was due 
to its decomposing power. Adsorption is in all probability excluded, 
since the small quantities of soil added to the water cultures could 
not have adsorbed the comparatively large quantities of the toxin in 
the higher concentrations. Evidently, the ameliorating effect of the 
soil on cumarin and vanillin demonstrated in the experiments with 
soil was due to different causes. 

The experiments did not show clearly that the depressing effect of 
cumarin and vanillin on the yield of the crops grown in soil, which 
was more pronounced with reference to the yield of grain, was due 
to the same causes which are operative in water cultures. On the 
other hand, there are some indications that the effect of the toxins 
is due to different causes in the soil than in water cultures. The 
appearance of the crops in the pots which received the highest con- 
centrations of the toxins was perfectly healthy. No inhibiting effect 
on the growth of the roots has been observed. A small quantity of 
soil added to the water cultures which contained cumarin entirely 



DAVIDSON: lOI'l'IXT OF CUMAKIN AND VANILLIN ON W IIIIAT. 2^7 



(leslrovcd its toxic cftVcts. All these considerations wonld lend to 
suj;j^est that tlie depression in yield ohserved was not a case of 
toxicity, which imphcs a certain niorpholo.^ical deraiii^enient or cer- 
tain chani^es in the composition and constitution of the plant suh- 
stance which interfere with the normal physiolo<^ical functions of the 
plant. 

Depressions in yields were ohtained with glucose, which suhstance 
one would hardly consider as a toxin. 

The depressing effects of cumarin and vanillin on the crops grown 
in soil might he due to the general effect of soluhle, non-nutrient 
organic matter. 

Soluhle organic matter may aft'ect the microflora of the soil, 
stimulating the growth of harmful organisms or the growth of 
microorganisms in general which would tend to tie up availahle 
plant food, or inhibiting the growth of useful bacteria. Thus, the 
results of these experiments would tend to show that the highest 
concentrations of cumarin and vanillin had a depressing effect on 
nitrification. 

The presence of soluble organic matter may affect to a certain 
extent the physical condition of the soil, forming protective films on 
the soil particles and thus interfering with granulation. 

Soluble organic matter which is not used by the plant may inter- 
fere, as a foreign substance present in the soil solution, with the 
absorption by the plant of the necessary elements of plant food. 

It might be added that these experiments were conducted under 
conditions which entirely excluded drainage, and that the frequent 
watering of the pots tended to compact the soil very much. It is 
possible that under proper conditions of drainage and cultivation, the 
results would be different. 

On the whole, it might be said that these experiments would hardly 
lend much support to the assumption that the presence in the soil of 
organic substances toxic in water cultures is a factor of considerable 
importance under field conditions, when the other factors of plant 
growth are normally good. 

Summary. 

I. The evidence offered in favor of the theory of soil toxicity is 
not sufficient to establish the fact that the roots of higher plants 
excrete substances harmful to themselves or to other plants. Neither 
is the evidence sufficient to estabHsh the presence in the soil of 
organic substances harmful to plants under normal field conditions. 

33 Konig, Hasenbaumer, und Glenk, 1. c. 



238 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

2. The concentrations of 600 parts per million of cumarin and of 
3,000 parts per million of vanillin, figured on the basis of the total 
moisture content of the soil, depressed to some extent the yield of 
wheat grown to maturity in pots. There are indications, however, 
that the efifect was rather on the soil than on the plant. 

3. The addition of small quantities of soil to water cultures en- 
tirely destroyed the toxic effects of cumarin, while it did not affect 
the action of vanillin. It is possible that vanillin is less readily 
decomposed by the microorganisms of the soil than cumarin, or that 
the decomposition products of vanillin are as toxic in water cultures 
as vanillin itself. 

4. In quartz cultures, cumarin has proved to be as toxic as in 
water cultures, while vanillin behaved approximately the same way 
as in the soil. Vanillin is evidently toxic only in a liquid medium 
when it is applied in mass, but not when it is distributed as films over 
quartz grains or soil particles. 

5. The ameliorating effect of phosphoric acid on the action of 
cumarin reported in Bulletin 77 of the Bureau of Soils would not 
seem to be due to its antagonistic behavior with reference to that 
toxin, since it did not behave in the same way in a balanced solution. 
The ameliorating effects reported might be due either to the residual 
effects of the base after the phosphate radical was used up, or to the 
fact that cumarin does not interfere with the absorption by the plant 
of phosphoric acid while it does interfere with the absorption of the 
other food elements. 

6. The behavior of toxic substances is so different in the soil than 
in water cultures, that one is hardly justified in drawing conclusions 
from results obtained with water cultures as to what might take place 
under actual field conditions. 

Acknowledgment. 

The writer is indebted to Dr. T. L. Lyon, under whose direction this work 
was done, for his kind assistance and valuable suggestions. 



Journal of the American Society of Agronomy. 



Plate IV. 




Fig. I. Method of Taking Soil Samples with Sampler for Soil Bacteriologists. 
(See article by H. A. Noyes.) 




Fig. 2. Graniteware Pots Showing the Outlet Tubes at the Bottom and the 
Hemispherical Funnels Inserted through the Wax Seal. (See article by A. G. 
McCall.) 



NOVICS: SOIL SAMl'MNC Fok il AC TICK l( )!.()( i I C'AL ANALNSIS. 239 



SOIL SAMPLING FOR BACTERIOLOGICAL ANALYSIS.' 

H. A. No YES, 

PuRnuK A(;ric:iti.tural Expkuimknt Station, LaFayicttk, Ind. 
Introduction. 

Ill connection with research work on an iVdanis fund ])rojcct in 
orchard nianaj^ement under investigation in this department it is 
necessary to follow the hiocheniical changes occurring in the soil. 
The plats are in clean culture, in cover crop, in sod and in sod with 
added mulching of grass and straw. This paper discusses the dif- 
ferent methods of sampling soils for bacteriological analysis which 
were considered in connection with this experiment. It gives the 
results of an investigation conducted to find out which method would 
furnish representative samples of soil and which would interfere 
least with the cultural practices or the root systems of the trees. It 
is hoped that these results may be suggestive to those who are under- 
taking similar bacteriological studies. 

There are three generally accepted methods for investigating the 
growth of plants : Field culture, plat culture, and pot culture. The 
method of sampling soil should be equally applicable where any of 
these cultural methods are practiced. 

Methods of Sampling Previously Employed. 

King and Doryland- have described a soil sampler which takes only 
a 5 c.c. sample of soil. This sample is too small to be of much use 
to the soil bacteriologist. To use this sampler efficiently, it is neces- 
sary to dig a hole at least a foot square to the depth the samples are 
to be taken. The digging of holes is detrimental to any investiga- 
tion which is to extend over a period of years, as the cultural methods 
are disturbed. Monthly samplings would soon destroy small plats if 
triplicate samples are taken on each plat. 

1 Contribution from the Research Chemistry and Bacteriological Laboratory, 
Purdue Agricultural Experiment Station. Received for publication May 10, 
1915- 

2 King, W. E., and Doryland, C. J. T., The Influence of Depth of Cultivation 
upon Soil Bacteria and their Activities, Kans. Agr. Expt. Sta. Bui. 161, p. 
225-228. 1909. 



240 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



The soil auger was used by Conn^ for taking soil samples for 
bacteriological analysis. The auger does not furnish samples which 
are suitable for bacteriological purposes. No matter how careful one 
is, some soil always falls back into the auger hole and the sample is 
scraped against the different layers of soil as the auger is pulled out 
of the ground. Brown,* in discussing methods of sampling, writes : 

" It was decided that this (the auger) method allowed opportunity for con- 
tamination of the deeper soil layers." 

The number of bacteria in soil that is covered with sod or vegetative 
mulching is different from the number in soil under different prac- 
tices of clean cultivation or dust mulching. The quantity of soil 
which falls back into the sampling hole on plaits under different 
systems of cultivation varies. On one plat it may be from the layer 
of soil having the greatest number of microorganisms, while on 
another plat it may be from the layer having the smallest number of 
microorganisms. 

The slice method is claimed by many to be the most accurate 
though not always the most practical method of sampling soil. This 
method when used for obtaining samples of soil for bacteriological 
analysis is open to the following objections: The spade is difficult to 
sterilize and to keep sterile because of its size. The cultural methods 
are interfered with, for holes have to be dug before the slices can 
be taken, and unless great care is exercised in cutting the slice varia- 
tions in thickness may easily change the average bacterial content of 
the soil 300,000 bacteria per gram of soil. To get even fair results 
with the slice method the soil has to be quite moist. In fact, some 
types of soil can not be sliced. 

The method of sampling employed at the Iowa station^ is described 
as follows : 

" The surface 2 or 3 inches of soil were removed from an area about 20 
inches square, the soil in that area was stirred and thoroughly mixed to a depth 
of 4 to 6 inches and the samples were drawn and taken to the laboratory in 
sterile glass jars." 

3 Conn, H. Joel, An Examination of Some More Productive and Some Less 
Productive Sections of a Field, Cornell Univ. Agr. Expt, Sta. Bui. 338, p. 70. 
1913. 

Conn, H. Joel, Bacteria of Frozen Soil, New York State Agr. Expt. Sta. 
Tech. Bui. No. 35, p. 9. 1914. 

4 Brown, P. E., Bacteria at Different Depths in Some Typical Iowa Soils, 
Iowa Agr. Expt. Sta. Research Bui. No. 8, p. 287. 1912. 

5 Brown, P. E., Bacteriological Studies of Field Soils I, Iowa Agr. Expt. Sta. 
Research Bui. No. 5, p. 194. 1912. 



iNOVKs: soil. sAMi'LiNc; I'OR i:.\( -ii'.u i( n .( )( ; !( \i - ANAI.^■sls. 241 



The followiiii^ is taken t'roin a rcccMit piiMication from tlic same 
station." 

" 'l lio iiK'tlitxl of sainpliiiR etni)K)yc(l in this work was tlu- same as lias been 
f^ivcn in the i)n'vit)us reports of the study of liekl soils. . . . 'l iu- nu'thod c<jn- 
tiniies to prove satisfactory and to justify claims which have hccii made for it." 

It socnis probable, however, that if the removal of the 2 or 3 inches 
of soil permits belter comj)arison 1)el\veen parts of fields or ])lats 
under the same systems of cultivation and croppin<^-, the removing of 
this layer of soil would seriously impair any comparison between 
jrlats in grass, in buckwheat, in corn and in siunmer fallow. 

Samples of soil taken by any of the methods so far cited are 
aerated and the layers of soil are mixed together in the field at the 
time the sample is taken. The new environment thus made for the 
soil organisms should be avoided, especially if the samples can not 
be analyzed for some hours after they are taken. 

The New Method of Sampling. 

A soil sampler for soil bacteriologists was recently advocated by 
the author of this article.'^ The object was to furnish a piece of 
apparatus wdiich would sample the soil accurately whatever the 
system of cultivation and become the container for the sample after 
it is taken. This sampler, which is shown in figure 13, is a brass tube 
9 inches in length and 2 inches in diameter, open at both ends. One 
end is sharpened to a cutting edge. This cutting edge is so made 
that the core of soil is cut out and the compaction of soil that is 
necessary in order to make room for the sampler takes place outside 
the tube. The cutting end is fitted with a tight fitting 2-inch brass 
cap. The uncapped end plugged with cotton makes the sampler 
complete. This sampler embodies at least four of the principles 
that a good sampler should have: (i) It is easily sterilized and kept 
sterile; (2) it is easy to use; (3) it takes and keeps the sample of 
soil free from contamination ; and (4) it is durable. The method of 
taking samples with this sampler is shown in Plate IV, figure i. 

The directions for using this apparatus are as follows : Plug and 
cap as many samplers as you wish to take samples of soil. Sterilize 
them in a hot air sterilizer and take them to the field. Remove the 
cap from a sampler, insert the driving head above the cotton plug 
and drive the sampler into the ground to the desired depth. Pull it 

6 Brown, P. E., Bacteriological Studies of Field Soils III, Iowa Agr. Expt. 
Sta. Research Bui. No. 13, p. 429. 1913. 

Noyes, H. A., A Soil Sampler for Soil Bacteriologists. Paper presented 
at meeting of Society of American Bacteriologists, December, 1914. Abstracted 
in Science, 42: 317. 1915. 



242 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



out, flame and return the cap, and sample is ready to take to the 
laboratory. 

Comparison of Methods of Sampling. 
Of the methods previously described the sampler for soil bacteri- 
ologists, the soil auger, the Iowa station method, and the slice method 
were thought worthy of investigation and comparison. The method 
of the Iowa station was modified in that a plat 2 feet square instead 
of 20 inches square was laid off and no surface soil was removed. 



mm 



c. 



Fig. 13. 



-Sampler for taking soil samples for bacteriological analysis 
A, Sampler complete ; B, sampler without cap ; C, cap. 



The method followed at the Iowa station samples the largest unit 
area of any of the methods, 2 feet square, hence that area is used 
as the basis for all comparisons. Two samples were taken from this 
plot with samplers, two with a 2-inch soil auger, two by attempting 
to mix all the soil in the plot to a depth of 9 inches, and two by the 
slice method. The method which gave the most uniform samples of 
the 2-foot area sampled was to be considered the best method of 
sampling soils for bacteriological analysis. For convenience, the 
method of the Iowa station is designated henceforth as the " whole 
plot method," and the soil sampler for soil bacteriologists as "the 
sampler." 

The procedure followed in taking the samples by the different 
methods follows : A plot 2 feet square was laid off, two of the 
samplers were driven to a depth of 9 inches on opposite sides of and 



NOVKS : sou. SAM I'M M, loR I'-ACi'l-'-K l( )l .( )( . U A I. A.\AI>\S1.S. 243 



within the ])l()t, drawn, capped and laid by. 'V\w\\ two samples were 
taken, one from each set of three horins^s made to a depth of 9 inches 
with a soil aui^er on each of those sides of the plot where the soil 
samplers had been driven. These two samples were ])nt in sterile 
IMason jars and immediately i)ut inside the carrying case away from 
the light. Next, the soil of the plot was spaded over until it ap- 
peared to be mixed thoroughly to a depth of 9 inches. A sample was 
then taken and put in a sterile Mason jar. The soil was mixed again 
and another sample taken. The soil w^as then thrown out, making a 
hole 2 feet square and 9 inches in depth. Lastly, on the same sides 
of the square and near where the former samples had been taken 
with the samplers and auger, tw^o more samples were taken by cutting 
slices of soil about i inch thick from the surface to a depth of 9 
inches. Sets of samples were taken in this manner on each of five 
dates. Counts were made from one set on 12 percent gelatin and 
on the other four sets on modified agar.^ Where one method was 
dropped the procedure remained the same for the other methods. 

In the laboratory, all samples of soil were mixed thoroughly. 
Fifty-gram quantities of the field soil then were put in sterile bottles 
with 200 c.c. of sterile water and shaken for five minutes. One c.c. 
of the soil emulsion thus made was put with 99 c.c. of sterile water 
and shaken thoroughly to give a dilution of i to 400. Dilutions of 
I to 40,000 and I to 400,000 were then made from this by adding 
10 c.c. ahquots of the less dilute samples to 90 c.c. of sterile water 
and shaking. One c.c. portions of the i to 40,000 and i to 400,000 
dilutions were plated on modified agar and incubated at 70 to 72° F. 
The figures given in the following tables are the average of triplicate 
plates and both dilutions. Some perhaps may contend that some 
figures given in the following tables are too uniform or that the dif- 
ferences are so small that the counts are meaningless. The uni- 
formity with which the samples were handled and the care used in 
weighing out the 50-gram aliquots of field soil taken for analysis, in 
making the dilutions, and in plating were bound to produce results 
that showed comparisons betw^een the different methods of sampling. 
The results obtained with the first set of samples are given in Table i. 

Set of Samples No. i. 

The samples from which results are reported in Table i were taken 
the day after a rain and were analyzed within two hours. Counts 

s Brown, P. E., Methods for Bacteriological Examination of Soils, Iowa 
Agr. Expt. Sta. Research Bui. No. 11. 1913. 



244 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



were made in 12 percent gelatin. The sampler gave the least varia- 
tion in counts on dupHcate samples of soil. It also gave a higher 



Table i. — Millions of Bacteria per Gram of Dry Soil as Determined by 4 
Methods of Sampling on a Brown Sandy Loam from a Clean-cultivated 

Young Orchard. 



Method of Sampling. 


Lot I. 


Lot 2. 


Average. 


Variation. 


Sampler 


6.707 


6.635 


6.671 


0.072 


Soil auger 


6.627 


8.999 


i 7.813 


2.372 


Whole plot 


4.976 


5-694 


5-335 


0.718 


Slice. 


4-739 


10.952 


7-846 


6.213 



count than the method using the whole plot, tending to show that 
soil can not be thoroughly mixed in place to a desired depth. The 
soil at the lower depth contained more bacteria, for the samples were 
taken soon after rain and some of them had undoubtedly been washed 
down into the soil. 

Set of Samples No. 2. 

The second set of samples was taken from a brown loam soil 
plowed in the spring and on which a dust mulch was maintained 
throughout the season. At the time the samples were taken, there 
was a 2-inch dust mulch. The samples were analyzed immediately 
after they were taken and the counts made on modified agar. The 
results are shown in Table 2. 



Table 2. — Millions of Bacteria per Gram of Dry Soil as Determined by 4 
Methods of Sampling a Brown Loam. 



Method of Sampling. 


Lot I. 


Lot 2. 


Average. 


Variation. 


Sampler 


II. 197 


10.920 


11.058' 


0.277 


Soil auger 


8.775 


10.178 


9-477 


1.403 


Whole plot 


8.532 


9.646 


9.089 


1. 114 




7.936 


11.357 


9-647 


3.421 



As shown in Table 2, the sampler again gave the largest and most 
uniform counts. .The counts obtained with the sampler are believed 
to be nearest the true bacterial content of the soil, as the dust mulch 
hindered in taking the slice, made mixing of the whole plot difficult, 
. and af¥ected the efficiency of the auger. 

Set of Samples No. 3. 

The third set of samples was taken from a sandy soil in bluegrass 
sod. This soil contained but 7 percent of moisture at the time the 
samples were taken. The samples were analyzed immediately and 
the counts made on modified agar. Table 3 shows the data obtained. 



NUVKS: soil- SAMIM-INC. i'oi^ lt.\( TI'.K K )l ,( )( ; l( AL ANALYSIS. 245 



Table 3. — Millions of /uu trria fu-r iiram of Dry Soil as / )cl,'riiiiii, (l hy ? 
Mclliods of Siuut'liiui a Sandy Soil in niucj/rass Sod. 



Method of Sampling:. 


Lot 1. 


lx)t a. 


Averager. 


Variation. 


Sampler 


2.76 


2.85 


2.81 


0.09 


Whole plot 


3-01 


2.89 


2.95 


0.12 




2.01 


1.87 


1.94 


0.14 



The soil aui^cr was not used in this sot, as the moisture content 
of the soil was so low that the soil would not hold in the auger. 
The sampler and the wdiole plot methods, on account of the low 
hacterial content of the soil, i,nve practically the same results. It 
seems that the whole plot method gives the higher count because many 
of the bacteria probably w^ere about the grass roots and this method 
gave a sample containing more sod than the others. Great difficulty 
was experienced in taking the slice samples and counts show that the 
samples thus secured were not representative. For the third time, 
it is evident that the sampler takes the more representative and uni- 
form samples from the two-foot-square plots. 

Set of Samples No. 4. 
The sampler having given the most representative counts and the 
least variation in counts on all three sets of soil, it was compared with 
other methods on the least uniform soil that was readily available. 
This was a mixture of manure, muck, compost, and sand which had 
recently been put into a new greenhouse over a gravel soil. The 
added material formed a layer about 6 inches in depth. The 
samplers, the slice and the method involving the mixing of the 2-foot 
square plot of soil were the methods used in this test. The samples 
w^ere taken as before in duplicate and then the whole set of samples 
was duplicated, giving two complete sets of samples. One set was 
analyzed immediately and the other was allowed to remain in the 
samplers and Mason jars for five days before being analyzed. The 
counts were made on modified agar. The results, expressed in 
millions of bacteria per gram of dry soil, are given in Table 4. 



Table 4. — MilHons of Bacteria per Gram of a Dry Greenhouse Soil, as Deter- 
mined by 3 Methods of Sampling. 



Method of Sampling. 


Analyzed Immediately. 


Analyzed After 5 Days. 


Average. 


Variation. 


Average. 


Variation. 


Sampler 


5-479 


0.988 


4.780 


0.279 


Whole plot 


6.181 


0.083 


0.239 


1-383 


Slice 


4.294 


0.318 


4-319 


1.232 



246 ■ JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The more a nonuniform soil is mixed the more uniform it becomes 
and thus it is to be expected that the whole plot method would give 
the most uniform results on this soil. The sampler appeared to take 
the more unrepresentative samples of soil as evidenced by the varia- 
tion between duplicates where the samples were anaylzed immediately 
after they were taken. It did, however, take samples more nearly 
representing the upper 9 inches of soil. From the composition of 
this soil, the greater number of organisms was in the upper mixtures 
which, in reality, were sampled by the whole plot method. The 
samples were air-dried and sieved and it was found that those taken 
with the samplers contained 10.5 percent of stone which would not 
pass through a 1.5 mm. sieve. Those samples taken by the whole 
plot method contained only 5.8 percent of stone which would not 
pass through the 1.5 mm. sieve. 

The counts made on the samples that were held five days showed 
that the samplers kept the soil in a condition more nearly approxi- 
mating that in the greenhouse. The samples were held at a lower 
temperature than the temperature of the greenhouse soil and thus a 
lowering in count is better than the same count or a larger count. 
The samplers kept the layers of soil intact and did not mix together 
the groups of microorganisms present at different depths or aerate 
the soil, as must be done if it is put in storage jars. The sampler 
keeps the soil in practically the same relationship to the air that it is 
in the field, whereas in the jars conditions are changed and errors 
arise that are dependent on the length of time that the samples are 
kept before analyzing. 

Changes in Nitrate Content. 
The following determinations (Table 5) of the nitrates present in 
the samples of greenhouse soil tend to show that the sampler will 
keep a sample of soil in the condition least favorable to changes in 
bacterial activities. 



Table 5. — Nitrates in a Greenhouse Soil Sampled by Various Methods as 
Determined at Time of Sampling and After Standing Five Days. 
(Determinations in milligrams of NO3 per gram of dry soil.) 



Method of 
Sampling. 


Analyzed Immediately. 


Analyzed After 5 Days. 


Change. 


Average, 


Variation. 


Average. 


Variation. 


Sampler 


0.305 


0.017 


0.314 


0.012 


0.009 


Whole plot .... 


0.298 


0.044 


0.366 


0.000 


0.068 


Slice 


0.263 


0.008 


0.343 


O.II4 


0.080 



NOVKS: sou. SAM I'M Nd lOK l!A( "I'l-.K l( H .( )( i I ( ' A I. ANALYSIS. 247 



Tlioro ;iri' (wo thills in Tabk' 5 that ari' appaicnl . I lie sampler 
(loos not show the least raiiL;e hi'tweeii diiplieales in cither ease, and 
it holds iho soil in that condition in which the nitrates remain prac- 
tically unchani^cd. The former is explained Ijy the nonuni formity 
of the soil. The latter i)ro\'es that the sampler does keep the soil 
in that concHtion in which the hiochemical activities tend to remain 
the same as under field conditions. 

Several tests made of soils under different conditions show that 
the soil is not appreciahly compacted in the sampler unless it is driven 
into the i>round with exceptionally heavy blows or the soil is excep- 
tionally loose. The results of these tests are shown in Tabl^ 6. In 
method A the sampler was driven into the soil w^ith three medium 
drives betw^een measurements, and in method B it was driven with 
three violent drives. 



Packing of Soil in Sampler. 

Table 6. — Effect on Compactness of Soil of Methods of Taking Samples with 

the Soil Sampler. 





Method A. 


Method B. 


Condition of Soil. . 


Depth of Soil. 


Com- 
pression. 


Depth of Soil. 


Com- 
pression. 


, „ , Around 
In Sampler. Sampler. 


^ , I Around 
In Sampler. ! Sampler. 



Tramped garden. 



Soy bean stubble. 



Bluegrass sod. 



Newly spaded garden 



Inches. 
2.50 
4-50 
6.50 

2.25 
4-75 
6.75 

2.00 

3- 25 

4- 75 
6.00 
7.00 

2.25 

3- 25 

4- 50 
6.75 



Inches. 
2.50 
4-75 
6.65 

2.25 
4-75 
6.87 

2.00 
3-25 
4.87 
6.25 
7-25 

2.50 
3-75 
5.00 

7.37 



Inches. 
0.00 
0.25 
0.15 

0.00 
0.00 
0.12 

0.00 
0.00 
0.12 
0.25 
0.25 

0.25 
0.50 
0.50 
0.62 



Inches. 


Inches. 


Inches. 


3.00 


3-25 


0.25 


4-50 


4.87 


0.37 


5-75 


6.25 


0.50 


3-75 


4.00 


0.25 


6.50 


6.90 


0.40 


2.87 


3.00 


0.13 


4-75 


4-75 


0.00 


6.25 


6.50 


0.25 








5.00 


6.50 


1.50 


6.75 


8.50 


1-75 













In this work an attempt has been made to investigate methods 
of sampHng as they vv^ould be followed in comparative studies. 
When samples are desired at different methods on a soil type there 
are two v^ays of taking them: (i) By taking the samples directly 
as you dig, bore, or drive down into the soil; and (2) by digging 



248 JOURNAL OF THE AMERICAN SOCIETY OF AGR< OMY. 

a hole and taking samples from the lateral surfaces of soil at the 
depths desired. In most work of this kind errors arise because the 
soil sample is aerated. Samplers of different diametprj and lengths 
would permit one, if he used those samplers of largest diameter first, 
to sample the soil to different depths without much contamination 
from the upper layers of soil. The upper portion of the core of 
soil obtained in this way should not be used in other than the first 
portion as that part of the sample has been exposed to the air. 

The sampler is adapted to horizontal use in pits, but here again the 
portion of soil nearest to the cotton plug should not be used for 
analysis, as this portion has been aerated. 

Summary. 

1. It is harder to obtain uniformly representative samples of soil 
for bacteriological analysis that it is for chemical and physical 
analysis. 

2. The errors which must arise from employing various methods 
of sampling soils for bacteriological analysis vary with the method 
employed, the physical condition of the soil, and the vegetative growth 
on the soil. 

3. Experimental work in investigating the growth of crops on soil 
is conducted by field tests, plot tests, and pot tests. The method of 
sampling should be one which can be used in connection with these 
tests. 

4. Different crops and different systems of cultivation effect 
changes in the environment of the bacteria in a given set of experi- 
ments and hence change the bacterial flora of the soil. 

5. An official method for sampling soils for bacteriological 
analysis should be one which would sample soils subjected to dif- 
ferent cropping and systems of cultivation with the same accuracy. 

6. Samples of soil used for bacteriological analysis should be repre- 
sentative, taken free from and kept free from contamination, and 
should be kept until analyzed in that condition in which the bacterial 
processes of the soil are not altered. 

7. A soil sampler for bacteriological purposes should be easy to 
sterilize, easy to manipulate, and durable. 

8. The slice method in comparison with the methods of the Iowa 
station and the soil sampler for bacteriologists does not give uni- 
formly representative samples of soil. 

9. The soil auger is unsuitable because it gives unrepresentative 
samples of soil for bacteriological purposes and because it can not 
be used at all on some soil types. 



NOYES j50IL SAMI'MNd I'OR ri:U K )l .( )( ■ I ( A I . ANAI,^■SIS. 249 



10. The iuc'IukI employed hy tlie Iowa station <^n'vcs Ix'ttcr resulls 
than either f'le shee method or the aii^ei- metliod. hut not as t^ood 
resuUs as are < htained w ith thi' soil sampler for soil haeterioloi^ists. 

Conclusions. 

The hrass soil s;uiij)ler descrihed in this article, which emhodics 
the principles of the steel cylinder used for sampling soil, the pipette 
box, and the cotton plug, is the best apparatus investigated for ob- 
taining samples of soil for bacteriological purposes, for it is easy to 
sterilize, easy to use, and is dura1)le. This sampler, when used in 
comparison with the Iowa station method, the soil auger method, and 
the slice method for taking samples of soil for bacteriological analysis 
on different types of soil and soil under different systems of manage- 
ment, takes the most representative samples for bacteriological pur- 
poses. It also prevents contamination of the sample and by becom- 
ing the container of the sample keeps it until analyzed practically 
under field conditions. This method of sampling does not interfere 
with the cultural methods followed on the plots or pots under in- 
vestigation. 

Acknowledgment. 

The author wishes to acknowledge with thanks the assistance of Air. Edwin 
Voigt in carrying out this investigation. 

The successful development of a sampler suitable for bacteriological pur- 
poses was in no small measure due to the cooperation of the Central Scientific 
Company. The author wishes to thank them for making trial samplers accord- 
ing to his specifications without charge. 



A NEW METHOD FOR THE STUDY OF PLANT NUTRIENTS 
IN SAND CULTURES.^ 

A. G. McCall, 
Johns Hopkins University, Baltimore, Md. 

The time is rapidly approaching when the agronomist must turn 
to water and sand cultures for the solution of the physiological prob- 
lems of plant nutrition which he is constantly encountering, not only 
in the field but also in his pot cultures. 

1 Contribution from the Laboratory of Plant Physiology, Johns Hopkins 
University. Received for publication July 6, 191 5. 



250 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The recent publications of Tottingham- and of Shive^ have sug 
gested the desirability and importance of having some method by 
which the effect of diflferent nutrient solutions upon plant growth 
might be studied in the presence of some soHd substance similar to 
the soil, but at the same time furnishing fewer chemical and biological 
complications. Acting upon this suggestion the writer has devised a 
method by which seedlings may be grown in sand and the nutrient 
solution renewed or modified almost as readily as in water cultures. 

The accompanying illustration (PI. IV, Fig. 2) shows the type of 
pot used in duplicating in sand some of Shive's work with wheat 
seedlings in solution cultures. The pots are of graniteware, • ap- 
proximately 12 X 12 centimeters inside, tapering slightly at the 
base and having a wide projecting rim at the top. When filled 
to within about 3 centimeters of the top, they hold 1,500 grams of 
dry quartz sand. To provide for the removal of the solution a small 
lead tube is soldered into the side as near the bottom as possible. 
The soldered joint and the lead tube are covered with paraffin to 
guard against lead poisoning and the outlet closed by means of ? 
short length of rubber tubing provided with a pinch-cock. The 
description of the method given in the following paragraphs includes 
the details of manipulation from the starting of the seedHngs to the 
harvesting of the plants. 

The seed is soaked in water and the seedlings grown, in the manner 
described by Tottingham,* to a height of about 3 or 4 centimeters, 
when they are ready to be transferred to the sand cultures. While 
the seed is being germinated 1,500 grams of dry quartz sand (previ- 
ously washed several times with distilled water) are weighed into the 
pot, the outlet at -the bottom of the pot being screened on the inside 
by means of a plug of glass wool inserted before the pot is filled. 
With the pinch-cock closed distilled water is now added to the pot 
until the sand is completely saturated, after which the pinch-cock is 
opened and the surplus water allowed to drain out through the tube 
at the bottom of the pot until the last free water has disappeared 
from the surface of the sand. A hemispherical clay funnel is placed 
in position as shown in the photograph and the pot is then ready to 
receive the seedlings. 

2 Tottingham, W. E., A Quantitative Chemical and Physiological Study of 
Nutrient Solutions for Plant Cultures, Physiological Researches, Vol. I, No. 
4, May, 1914. 

3 Shive, J. W., A Three-Salt Nutrient Solution for Plants, Am. Jour. Bot, 
4: 157-160, April, 1915. 

^L. c, p. 176. 



m'cai.i,: si'lidn' of im.ant nutui i'.nts. 251 

Alter carclul scK'clion tor niii t'ortnil)', llic sri'dlinos, six in iiuni- 
l)cr, arc planlcd o(|ual (listaiicrs aj)arl on a circ-lc drawn midway 
between the edge of tlie funnel and the wall of the ])ot. ( "are is 
taken to have the seedlinj^s at such depth that the toj) of the i^rain is 
just level with the surface of the sand. After all of the seedlings 
are in place the pinch-cock is closed and the pot is tapped gently on 
the top of the table until free water appears on the surface of the 
sand. This manipulation serves to pack the sand around the roots 
of the seedlings and at the same time to level the surface of the sand 
preparatory to putting on the seal of Briggs and Shantz''^ wax. The 
surplus water is then drawn out of the pot by application of suction 
(by means of an aspirator) to the tube at the bottom and a thin layer 
of the melted wax is flowed over the surface, completely covering 
the surface of the sand between the funnel and the wall of the pot. 
Care should be taken not to have the wax too hot, or the seedlings 
may be injured at the point of contact between the wax and the plant. 
The surface must be sealed to prevent loss of water by evaporation 
from the surface of the sand and of course the walls of the pot must 
be impervious to moisture in order that transpiration can be meas- 
ured and the concentration of the nutrient solution controlled. 

The pot is now ready to receive the nutrient solution, which is 
added through the funnel at the top while the water is being removed 
at the bottom by the application of suction to the outlet tube. A 
double or triple portion of the nutrient solution is passed through the 
sand at this first application in order to flush out the distilled water. 
The pot is now placed on the scales and the removal of solution is 
continued until the sand has been reduced to the desired moisture 
content, w^hich should be as near the optimum as possible. At the 
end of each three-day period the pot is weighed and sufficient water is 
added through the funnel to bring the system back to its original 
weight. A fresh nutrient solution is now added in the desired 
amount (250 c.c. for pots of this size), while an equivalent quantity 
of solution .is removed at the bottom. A nutrient solution of the 
same concentration may be used throughout the entire period of 
growth, or it may be varied from time to time as the plants continue 
to develop. The plants may be harvested at any time by removing 
the wax seal and cutting them level with the surface of sand. If 
desired, the roots may be recovered from the sand by washing them 
out with a jet of water. The weight records will give the trans- 

5 Briggs, L. J., and Shantz, H. L., The Wilting Coefficient for Dif¥erent 
Plants and its Indirect Determination, U. S. Dept. Agr., Bur. Plant Indus. 
Bui. No. 230, p. 13, 1912. 



252 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

piration of each culture and the harvest records can be made to 
include the dry weights of both tops and roots. 

This method also furnishes a means by which the original con- 
centration of the solution can be compared with its concentration 
after contact with the soil and with the plant roots. The method is 
superior in many ways to water cultures because it permits the plants 
to be grown under conditions that approximate those found in the 
field, so far as the substratum is concerned, and it seems probable 
that with some slight modifications which are now in progress it will 
be possible to apply the method to cultures grown in sandy and 
sandy loam soils. 

AGRONOMIC AFFAIRS. 

NOTES AND NEWS. 

Paul S. Baker has been appointed assistant in agronomy at the 
Pennsylvania college and station. 

The resignation of Dr. M. A. Brannon as president of the Uni- 
versity of Idaho, announced in the July-August Journal, has been 
withdrawn and Dr. Brannon will remain at Moscow. 

James W. Cantwell, formerly superintendent of schools at Fort 
Worth, Texas, has been elected president of the Oklahoma College 
of Agriculture. 

During the latter half of May and the first half of June Geo. N. 
Cofifey of the University of Illinois assisted the Ontario Agricultural 
College in beginning a general soil survey of the Province of Ontario. 
This is the first soil survey work which has been done in Canada. 

Kenneth Cole is now assistant in agronomy at the Maryland 
station. 

John Lee Coulter of the Knapp School of Country Life, Peabody 
College, Nashville, Tenn,, has been elected dean and director of the 
West Virginia college and station. Dr. Coulter's work has been 
largely along the fine of rural economics. For two years he was 
assistant professor of rural economics at the University of Minnesota 
and more recently was special agent in charge of editing and com- 
piHng the figures on agriculture for the 1910 census. 

F. L. Duley has been appointed research assistant in soils at the 
Misouri station. 



ACRONOM IC A 1- 1' A IKS. 



E. C. Johnson, for llic i)ast ihrcc years in charge of farmers' in- 
stitutes in Kansas, has ])een elected dean of the extension division of 
the Kansas collei^e, succeeding J. 11. Miller, who is now dean of 
extension in Arkansas. 

Lewis A. Merrill, for a numher of years agronomist of the Utah 
station and more recently engaged in commercial work in agronomy 
at Salt Lake City, was killed in an automohile accident near that 
city, on June 1. lie had heen a memher of this society since 1909. 

C. P. Norgord has heen appointed commissioner of agriculture in 
Wisconsin. He will be at the head of the newly organized depart- 
ment of agriculture in that state, in which several offices having to 
do with agricultural affairs are now combined. 

Glen S. Ray, a graduate of the Colorado Agricultural College, has 
been appointed assistant in farm crops in the University of Idaho. 

Robert Stewart, for the past several years professor of chemistry 
and chemist of the Utah college and station, on September i became 
associate professor of soil fertility in the University of Illinois and 
assistant chief in soil fertility in the Illinois station. 

Theodore Stoa of the North Dakota station has been appointed 
a scientific assistant in cereal investigations in the U. S. Department 
of Agriculture. 

Chas. S. Van Nuis has been appointed associate agronomist in the 
New Jersey station and manager of the college farm, succeeding 
Irving L. Owen, who becomes county farm demonstrator in Middle- 
sex County. 

The following officers were elected at the meeting of the Great 
Plains Cooperative Association at Mandan, N. Dak., July 14-16: 
President, Director W. L. Carlyle of the Oklahoma station ; vice- 
president, Supt. J. F. Ross of the Amarillo Cereal Field Station; 
secretary, E. C. Chilcott, of the U. S. Department of Agriculture; 
and as additional members of the executive committee, W. W. Burr 
and C. W. Warburton of the U. S. Department of Agriculture and 
L. E. Call of the Kansas station. 

H. H. Bartlett, of the bureau of plant industry, U. S. Department 
of Agriculture, has been appointed assistant professor of botany in 
charge of genetics in the University of Michigan. 

W. C. Etheridge, for the past three years engaged in graduate 
study at Cornell University, is now in charge of the department of 
agronomy in the University of Florida. 



2 54 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



E. P. Humbert, agronomist of the New Mexico college and station, 
has been appointed dean of agriculture. J. G. Hamilton has been 
appointed assistant agronomist in New Mexico. 

John H. Voorhees, formerly agronomist in the extension division 
of the New Jersey college, is manager of Franklin Farms, Mendham, 
N. J. ■ 

Louis Wermilskirchen, scientific assistant at the Amarillo (Tex.) 
Cereal Field Station of the U. S. Department of Agriculture, has 
been appointed superintendent of the State station farm at College 
Station, Tex. 

Joseph E. Wing, a prolific writer of agricultural books and news- 
paper articles, died September lo of pellagra in a sanitarium near 
his home, Mechanicsburg, Ohio. 

Interstate Cereal Conference. 

An Interstate Cereal Conference was held at the University of 
California, Berkeley, Cal., June 2, 191 5. Dr. J. W. Gilmore of the 
University of California was elected chairman, and Chas. E. 
Chambliss of the U. S. Department of Agriculture, secretary. The 
executive committee consists of the officers and Messrs. M. A. Carle- 
ton, F. S. Harris, and Bert D. Ingles. Fifteen papers were presented 
at the meeting. On June i the cereal crops in the vicinity of Stock- 
ton, Cal., were inspected by many of those who attended the con- 
ference. On June 3 and 4 the cereal experiments of the University 
of California at Davis and of the Office of Cereal Investigations, 
U. S. Department of Agriculture, at Chico and Biggs, Cal., were 
inspected. 

Meetings of the Society. 

A joint session of the American Society of Agronomy and the 
Great Plains Cooperative Association was held at Mandan, N. Dak., 
July 14-16, 1915. About 80 persons attended the meeting and about 
25 papers were presented. More than half of those in attendance 
and more than half of those who presented papers were members of 
the society. 

The eighth annual meeting of the American Society of Agronomy 
was held at Berkeley, Cal., August 9 and 10. The program was 
presented practically as published in the July-August number of the 
Journal. Officers for 1916 were elected as follows : President, 
C. R. Ball of the U. S. Department of Agriculture; first vice-presi- 
dent, Alfred Atkinson of the Montana station ; second vice-president, 



ACRONOM IC AFFAIRS. 



A. N. TTiinic of llir South 1 ).ik()(.-i station; secretary, W. War- 
burton, of the IJ. S. I )e|)artnK'nt of A_<^n'cnlture ; and treasurer, 
George Roberts of the l\eiitucky station. A full repoit of tlie 
meeting and of the various officers and committees will be ])ubli,shcd 
in the November- l)eceml)er Journal. 



MEMBERSHIP CHANGES. 

The membership reported in the July-August number of the 
Journal was 444. Fifteen new members have been added since 
that time, while i has resigned and i has died, making the total mem- 
bership at present 457. The number of new members received in 
191 5 is now 93. The names of members deceased and resigned, new 
members not previously reported, and recent changes of addresses 
are as follows : 

Member Deceased. 
L. A. Merrill. 

Member Resigned. 
D. S. Fox. 

New Members. 

Bailey, C. H., University Farm, St. Paul, Minn. 
Bassett, L. B., 2095 Dudley Ave., St. Paul, Minn. 
Emerson, F. V., 715 Boyd Ave., Baton Rouge, La. 
Hall, Thos. D., 301 Bryant Ave., Ithaca, N. Y. 
Harper, J. D., Purdue University, West LaFayette, Ind. 
Harrington, Oscar E., Experiment Station, East Lansing, Mich. 
Knutson, Geo., Great Western Sugar Co., Longmont, Colo. 
LuACES, Roberto L., Granja Escuela, Camagiiey, Cuba. 
Maxson, a. C, Great Western Sugar Co., Longmont, Colo. 
MiYAKE, Koji, 2316 Fulton St., Berkeley, Cal. 
Pieters, a. J., 340 Blair Road, Takoma Park, D. C. 
Piper, Geo., Glendive, Mont. 

Rudolph, E. G., The Dakota Farmer, Aberdeen, S. Dak. 
Thysell, John C, Dickinson Substation, Dickinson, N. Dak. 
VoiGT, Edv^in, 20 Waldron St., West LaFayette, Ind. 

Addresses Changed. 

CuRREY, Hiram M., c/o C. S. Bowne, Aumsville, Ore. 

Douglass, T. R., Iowa State College, Ames, Iowa. 

Dynes, O. W., New York State College of Agr., Ithaca, N. Y. 



256 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Lechner, H. J., Washington State Normal School, Ellensburg, Wash. 
McCall, Arthur G., Ohio State Univ., Columbus, Ohio. 
Stewart, Robt., Univ. of 111., Urbana, 111. 
Mackie, W. W., 1358 Scenic Ave., Berkeley, Cal. 
YoDER, P. A., Cairo, Georgia. 

COMING EVENTS. 

Under this caption it is proposed to keep standing a schedule of 
coming meetings of various organizations more or less closely con- 
nected with agronomy. Secretaries of such bodies are invited to 
furnish information regarding their meetings. 

Seventh Graduate School of Agriculture. 
Massachusetts Agricultural College, Amherst, Mass., July, 1916. 

Second Pan-American Scientific Congress. 
Washington, D. C, December 27, 191 5 — January 8, 1916. 

LOCAL SECTIONS. 

Iowa State College and Experiment Station. 
President, Ross L. Bancroft. 
Secretary, R. A. Needham. 

Kansas Agricultural College and Experiment Station. 
President, W. M. Jardine. 
Secretary-Treasurer, C. C. Cunningham. 

Washington, D. C. 
President, H. N. Vinall. 
Secretary-Treasurer, P. V. Cardon. 



JOURNAL 

OF THE 

American Society of Agronomy 



Vol. 7. November-December, 1915. No. 6. 



THE WORK OF THE AMERICAN AGRONOMIST. 

Charles E. Thorne, 

Ohio Agricultural Experiment Station, Wooster, Ohio. 

(Presidential address before the American Society of Agronomy, August 

9, 1915-) 

The ultimate purpose of the work of the scientific agronomist is 
to increase the production of food and clothing for humanity. He 
has been called to this work in response to the evident proposition that 
population can not continue indefinitely to increase at the rate which 
is now prevailing unless there is a corresponding increase in the rate 
of food production. It is true that the lines of human increase and 
of food production, for the world at large, are approaching each 
other far less rapidly than has been anticipated by some who have 
prophesied on this point, but nevertheless none can deny that the 
average acre must be taught to yield more liberally than it is now 
doing if future generations are to be fed and clothed adequately. 

Within the space of a lifetime the art of agriculture has passed 
through a tremendous revolution. I myself have witnessed the 
reapers bending their backs to gather the wheat on an Ohio farm 
with an implement which had been practically unchanged since man 
first learned the use of iron. I have seen the mowers swinging their 
way through the meadow and have listened to the rhythmic thud of 
the flail on the thrashing floor. I have seen the wooden plow, with 
its iron share, lying only recently discarded in my grandfather's barn- 
yard, and have witnessed every forward step from these crude imple- 
ments of husbandry, which had been practically unchanged for thou- 
sands of years, to the elaborate farm machinery of today, by which 

257 



258 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

one rlian can accomplish more in many lines of work than was possible 
to ten men sixty years ago. 

This progress in mechanical invention, which has wrought a still 
greater revolution in transportation than in agriculture during the 
same period, has made it possible to spread our corn and wheat fields 
over this new land of ours until we have reached the limit of the 
naturally watered land and are now attacking the desert with great 
schemes of irrigation. The westward tide of migration, reaching the 
limit of the free land, has now turned upon its course and is starting 
eastward. 

This expansion in production has been accompanied by a still 
greater increase in population. During the 40 years from 1871 to 
191 o our production of wheat and corn doubled, as measured in 5- 
year periods. From 1881 to 1900, however, we were exporting more 
than one-third of our total wheat crop, while our exports for the 
5 years from 1908 to 1912 averaged less than 15 percent of the crop, 
although the total production of wheat in the United States was 
greater during that period than for any other similar period in the 
history of the country. Our exports of corn have never reached any 
considerable proportion of the crop, the highest rate of exportation 
being an average of 10 percent of the total crop during the 5 years, 
1 896-1 900, but it fell to less than 2 percent during the 5 years, 
I 908-1 91 2. 

The prediction made and widely published about 25 years ago that 
the United States would cease to be an exporter of wheat before the 
beginning of the present century has therefore fallen very far short 
of fulfillment. It cannot be questioned, however, that the tendency 
the world over is strongly towards the overtaking of production by 
consumption and that the coming generations of farmers will need all 
the help that the scientific agronomist can give them if the world is 
to continue to be sufficiently fed and comfortably clothed. 

Mechanical invention can certainly not make another such advance 
in the production of farm crops as it has done in the past 60 years. 
There will be further improvements, without doubt. The plow, 
harrow and cultivator will probably be drawn chiefly by gasoline or 
electricity within the next 20 years, and the cost of transportation 
will certainly be further reduced by the motor truck, driven over 
improved roads. I freely admit that no man in my boyhood days 
could have predicted the progress which I have witnessed, but I 
believe that we have reached a plane of knowledge with reference to 
the laws which govern mechanical operations which justify us in 



tiiornk: work of tiiI': a.mi;ki( AN ai.ko.noai ist. 



259 



;issiimin<^ that the major part of the road hctwccMi what has l)ccn and 
what shall he in the mechanics of agriculture has 1)een traversed. 

Moreover, mechanical invention has not on!)' done very little 
towards the increase of crop yields, hut it has l)een of incalculahle 
aid to the soil rohher. The machinery for makinj^ drains .and drain 
tiles and for the compounding and distrihutiou of fertilizing materials 
has contributed to the conservation of soil fertility. On the other 
hand, each improvement in tillage, harvesting and transporting ma- 
chinery that has reduced the amount of human labor required per 
acre in crop production and transportation has thereby made it pos- 
sible the more rapidly, extensively and completely to deplete the soil 
of its fertility. It was the automatic grain binder and the trans- 
continental railroad which made possible the exploiting of the bonanza 
wheat farms of the Northwest 30 years ago, and which brought 
down the price of wheat to a point below the cost of its production on 
the eastern farm. The estimates of the United States Department of 
Agriculture show, however, that the average yield of wheat per acre 
for the country as a whole remained stationary at about twelve 
bushels until 1890 — or until the effect of modern scientific research 
in agriculture began to be manifested in our wheat fields — notwith- 
standing the vast area of new land which was annually being brought 
under the plow. 

More thorough drainage and deeper and more perfect tillage enable 
the crop to extend its feeding area and bring the stores of plant food 
in the soil more rapidly into available form, by improving the condi- 
tions for the chemico-biological action by which the first steps are 
taken in the conversion of stones into bread. The experience of the 
ages has shown that, excepting the few small areas in which the 
fertility of the soil is maintained by materials carried from other 
lands and deposited in periodic floods, the natural stores of plant food 
in the soil, abundantly sufficient as they seem, when viewed in the 
crude mass, to maintain crop yields indefinitely, are nevertheless so 
inert that the portion which the crop is able annually to obtain, even 
under the best systems of drainage and tillage, sooner or later falls 
below the point of profitable cultivation. 

The course of crop production under the empirical system of agri- 
culture which has hitherto prevailed is well illustrated by the statis- 
tics of corn and wheat production in Ohio, in which State these 
statistics have been collected by the township assessors since 1850. 
From its earliest history Ohio has been a large producer of both 
wheat and corn. The pioneer farmer found there a soil and climate 
admirably adapted to the growth of both grains, and he found corn 



26o JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

already extensively cultivated by the Indian. The lake on the north 
and the river on the south furnished facilities for transporting his 
crops to market before the advent of the railroad, and when that came 
it found Ohio lying in the direct pathway between the East and the 
West, so that there has been every inducement to extend to the 
utmost the production of these grains. 

The outcome has been that for the 40 years from 1850 to 1889, 
Ohio produced about 10 bushels of wheat per capita of population, 
except for a few years during the Civil War and immediately after, 
the production keeping pace with the increase of population, which 
averaged nearly half a million for each decade. This gain in pro- 
duction, however, was due chiefly to expansion of area, the increase 
in yield per acre during the 40 years amounting to not more than 
a bushel. With the end of the eighties there began a decrease in the 
area sown to wheat, due largely to the depression in prices, and for 
the 10 years from 1900 to 1909 our production was but 6 bushels 
per capita, although there was a further increase of a bushel and a 
half in the yield per acre, an increase probably due in a considerable 
degree to the Hmitation of the wheat area to the land better adapted 
to this crop. Should the population of Ohio continue to increase as 
it has done during the last 40 years and should there be no further 
increase in the area sown to wheat nor in the yield per acre, that State 
will not be producing bread enough for its people 20 years from 
now. 

What is taking place in Ohio will follow, sooner or later, in the 
nation as a whole. There will of course be some extension of the 
area given to wheat as soon as encouragement is offered by better 
prices. Ohio grew half a million more acres of wheat during the 
eighties, when the price averaged above a dollar a bushel, than has 
been grown since the beginning of the present century. An average 
price for a few years of a dollar and a quarter to a dollar and a half 
per bushel would probably add a million acres to our present area in 
wheat and ten to twenty millions to that of the United States, but 
while no limit can be set to our increase in population, there is a very 
definite limit to the possible area of our wheat fields. 

There will also be an extension of the area sown to wheat in other 
countries. The possibilities of South American and South African 
wheat fields have not yet been sounded, nor has the limit of wheat 
production been reached in Siberia and Manchuria. The North 
American wheat grower will therefore have plenty of competition for 
a long time to come, and the efiforts of the American agronomist 
should be directed towards reducing the cost of production through 



TiiORNi-:: WORK OF i iii': ami:ri( AN acuonom ist. 261 

l)etter cultural methods, through iniprovcMncnt of variclii-s, and 
through more effective feediuj^ of the plant. 

One of the greatest sources of waste in the agriculture of Ohio is 
the cultivation of land which, through lack of drainage and of rational 
fertilization, can not by any possibility yield a full crop. hOr the 
10 years from 1903 to 1912 our average yield of wheat was hut 15)4 
bushels per acre, while in many counties it was less than 12 bushels. 
This means that a large portion of the crop is grown on land which is 
giving an inadequate return for the labor expended upon it. The 
inferior crops which are grown on this land go to swell the total 
volume thrown on the market and thus to depress prices, while the 
men who are producing such crops are receiving less for their work 
than the wages of the common day laborer. We are talking effect- 
ively about the elimination of the loafing cow from our dairy herds ; 
let us begin to talk about eliminating the loafing acre from our wheat 
and corn fields. We are growing twenty-eight million bushels of 
wheat in Ohio on nearly two million acres of land, and one hundred 
and eleven million bushels of corn on nearly three million acres. We 
are also gowing nearly a million and a half acres of oats, which 
yield but 34 bushels per acre. It is safe to say that the total 
produce of these six million acres could be grown on two-thirds the 
present area, and at a saving of six to eight million days' labor, under 
such a system of drainage, crop rotation and fertilizing as science is 
now ready to point out, and that this change could be brought about 
within ten years' time, if the cooperation of the farmer could be 
secured. There is no immediate urgency for a greater total produc- 
tion of wheat, but there is a tremendous urgency for a more econom- 
ical production. 

If we can demonstrate to the farmer that he can produce his present 
yields on fewer acres and with less labor and thereby induce him to 
turn back to nature a part of the land over which he is now toiling 
without profit or at an actual loss, even though this abandoned land 
be occupied by briers and thistles, both he himself and his and our 
posterity will be benefited. Both the wisely cultivated and the wisely 
;mcultivated land will gain in fertility, so that when the generations 
that are to follow us need more bread there will be a rested and 
recuperated land ready to give it to them. 

The first step towards the attainment of this end, east of the 
Missouri at least, is drainage. At a rough estimate, possibly one 
acre in a hundred in Ohio is naturally sufficiently drained by under- 
lying gravels or stratified rocks. Possibly two acres in a hundred 
have been sufficiently drained by tiles, and possibly thirty acres in a 



262 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

hundred are partially drained, either naturally or artificially, but I 
am confident that more than two-thirds of the land now under plow 
in the state is in urgent need of drainage. If the wettest half of this 
two-thirds were at once seeded to grass and the labor thus saved from 
its cultivation expended in draining the remainder a long step would 
be made towards better conditions. 

There are hundreds of thousands of acres of land in Ohio on which 
a dressing of lime would immediately return lOO to 200 percent on its 
cost. Not all our land needs lime so urgently as this, but the 
agronomist is now prepared to advise the farmer intelligently on this 
point. This is the second step forward, for when the land needs 
lime neither tillage nor drainage nor crop rotation nor manuring nor 
fertilizing can perform its full function. 

For nearly a century there has been a steady outflow of phosphorus 
from Ohio's farms, carried in the pioneer days in the wheat which- 
was shipped east by the lake or south by the river and in the bones 
of the cattle which were driven over the mountains to the eastern 
cities or in those of the hogs which went down the Ohio to be con- 
verted into energy for the production of sugar and cotton. In later 
days this phosphorus has been dispersed still more widely as facili- 
ties for transportation increased, and today we find all- the older 
Ohio soils so hungry for it that a judicious investment in this element 
returns with a few months from 200 to 500 percent. 

Northwestern Ohio is a great, flat plain, very deficient in natural 
drainage, but with large areas of rich, black soil. Systematic drain- 
age by organized effort has been carried farther here than in any 
other region of the State, and this region has increased its yields of 
corn by more than 8 bushels and of wheat by more than 3 bushels 
per acre during the 60 years of our statistical record. 

Northeastern Ohio is more rolling and very little draining has been 
done, but a larg'er use of commercial fertilizers has been made in this 
quarter than in any other section of the State, the fertilizers being 
applied chiefly to the wheat crop. The outcome has been a larger 
gain in this section in the yield of wheat during the 60 years than in 
any other quarter. 

Between drainage in the northwest and fertilizing in the northeast 
the northern third of Ohio now exceeds the average of the State in 
corn yield by more than 3 bushels and in wheat yield by nearly 
2 bushels per acre, but the total yields attained in this section are 
only half what has been attained when drainage, liming, manuring, 
fertilizing and systematic rotation of crops have all been laid under 
contribution. 



TIIOKNi:: WORK OF TIIIC AMlCKIfAN ACRONOM 1ST. 263 

J^rainaf^e, Hnic and phosphorus are not the only anicnchiicnts and 
rccnforccnients required by the average Ohio soil. The system 
of husbandry which has rechiced its stock of phosphorus has also 
drawn heavily upon its stores of nitrogen and potassium, and restitu- 
tion of these also must be made in some manner if potential crop 
production is to be attained. On some of the more exhausted lands 
it is possible to use commercial nitrogen and potassium with profit, 
but in a very great majority of cases, and ultimately in all, the object 
should be to obtain these elements almost exclusively from the air 
and the soil and to pilot the farmer successfully in this direction will 
require the aid of all the resources of agronomic science. 

We have not as yet measured the capacity of the nitrogen-fixing 
organisms which we have so recently discovered. One thing is cer- 
tain, and that is that we can not build up the nitrogen supply in an 
impoverished soil by growing an occasional crop of clover and taking 
oflf the hay. It is equally certain that we can not afford to ignore 
the help which the leguminous crops offer us in this direction. 

Next to drainage and lime and phosphorus, the greatest need of 
the Ohio farm is nitrogen. How to secure this nitrogen most 
economically is the most intricate problem set before the agronomist. 
It is a problem which can not be solved in the chemical or bacterio- 
logical laboratory, nor can it be solved without the aid of the chemist 
and the bacteriologist, both working together and hand in hand with 
the agronomist, restricting this term for the moment to him who 
directs the practical management of farm crops as they are grown in 
the open field. 

The harnessing of atmospheric nitrogen through the aid of elec- 
tricity, announced by Sir William Crookes seventeen years ago as 
commercially accomplished and verified by a present annual combina- 
tion of such nitrogen in quantities .equivalent to that contained in 
more than 100,000 tons of nitrate of soda, with results so satisfactory 
that the capacity of the producing plants is being greatly increased, 
has indefinitely postponed the possibility of the supply of human 
food being restricted for want of nitrogen. This epoch-marking 
discovery, however, does not absolve us from the duty of pointing out 
to the farmer the methods by which the larger part of the nitrogen 
required by his crops may be obtained in less costly form than either 
nitrate of soda or cyanamid. 

When scientific research in agriculture was organized under 
national legislation in America it was a new thing in the world and 
the popular concept of such research was extremely hazy. The term 
" agronomy " did not come into general use for many years, and those 



264 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

of US who set ourselves to the study of the problems that are now 
included under this term went at our task in many and devious ways, 
because there was no lamp of experience to guide our feet. Grad- 
ually some semblance of system is being evolved out of this chaotic 
condition, and I believe that we have come to the time when a few 
general principles may be enunciated as having an important bearing 
upon the conduct of agronomic research. 

The first of these is the necessity for a more definite knowledge of 
the soils upon which we are working. Whether our object be the 
increase of production through a more efifective feeding of the plant 
or through a better adaptation of variety to environment, it is of the 
first importance that we get acquainted with our soils. The soil 
survey is the first step in this direction and it should be energetically 
pushed forward in every State. But the soil survey is a very super- 
ficial and inadequate form of research unless accompanied by chemical 
and biological studies and by field experiment. 

By the soil survey we may classify our soils on the basis of their 
geological history and physical characters, and thus may be enabled 
to limit the far more difficult and costly field experiment to general 
soil types, but unless the survey is followed and its findings in- 
terpreted by field experiment it will have very little value. We may 
learn much by chemical analysis and by pot-cultural work, but the 
final answer to our questions can be obtained only in the field. 

A point of fundamental importance In field experiment is the 
necessity for continuity of effort. Experience has shown that 
seasonal conditions may completely reverse the outcome of an ex- 
periment with fertilizers or varieties, and that definite advice as to 
farm practice can not be safely formulated until the work has passed 
through a considerable number of our changing seasons. The prob- 
lems which confront us can never be solved by intermittent, desultory 
methods. The field experiment is one of the most intricate and 
baffling methods of investigation. The variations in soils, the chang- 
ing seasons, the interplay of the chemical and biological factors in 
the soil of which we know so little, call for the exercise of the highest 
scientific training for the correct interpretation of its results, but 
because this work is tedious, difficult and often disappointing we are 
not excused for neglecting it. 

The organization of scientific research in agriculture provides, and 
I believe wisely, for a single center of such research in each State, 
but the agronomist who limits his work to the single farm upon 
which his station happens to be located or who expects to complete 
his work within a season or two will make a fatal mistake. 



WOLFE : EFFFXT OF CROSSING VARIKTIKS OF CORN. 



265 



The investigator whose goal is the classification of ol)jccts, the 
study of their composition or of their physical relations, may establish 
his facts from a comparatively few observations. The chemist, 
under the conditions of absolute control which prevail in his labora- 
tory, may determine his weights and measurements with such ac- 
curacy that a single analysis may define the composition and character 
of the object under investigation, but the agronomist, whose chief 
reagent is that most mysterious of all natural forces, the life prin- 
ciple, and whose work is to study the relation of this princi])le to the 
physical, chemical and vital forces of soil and air and sunshine, under 
the ever-varying whims of climatic change, must go at his work in 
the knowledge that when the grayness of age has overtaken him his 
task will have been only fairly begun. 

FURTHER EVIDENCE OF THE IMMEDIATE EFFECT OF 
CROSSING VARIETIES OF CORN ON THE SIZE 
OF SEED PRODUCED.! 

T. K. Wolfe, 

Virginia Agricultural Experiment Station, Blacksburg, Va. 
Introduction. 

There is abundant evidence which goes to prove that crossing 
varieties or strains of corn frequently increases the yield, especially in 
the first hybrid generation. Corn differs from most other plants in 
that the effect of crossing can be seen the current year. This is due 
to xenia, or the hybridization of the endosperm as well as of the 
embryo. 

The first recorded experiments along this line seem to have been 
made by Professor Beal (i),^ beginning in 1876, and these experi- 
ments were followed by those of Sanborn (15), McCluer (12), 
Morrow and Gardner (13), Shull (16), East (7), and Collins (5). 

Hartley (9) found that in one instance generation hybrid seed 
proved 20 percent more productive than either parent. Hayes and 
East (11) obtained an increase in yield of the hybrid over the parent 
in five out of seven crosses. The increase varied from 7 to 44 bushels 

1 Paper No. i from the Department of Agronomy, Virginia Polytechnic Insti- 
tute and Agricultural Ex;^eriment Station. Received for publication July 12, 
1915- 

2 Figures in parenthesis refer to publications similarly numbered in the lit- 
erature cited at the end of this paper. 



266 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

per acre. Hartley, Brown, et al. (lo) obtained increases in yield from 
some crosses and decreases from some in tests made in Maryland, 
California, Texas and Georgia. From their results the writers con- 
clude that careful tests must be made in a locality before the farmer 
can be advised to plant first generation hybrids of certain strains or 
the pure strains themselves. BeUing (2) found that the hybrid seed 
of Mosby pollinated by Cuban yielded over one-third more shelled 
corn to the row than did the pure Cuban or Mosby. 

All of the results of experiments given above are derived from 
yields of hybrid seed in the generation. Collins (6) and also 
Carrier (3) found that the immediate effect of crossing corn was to 
increase the yield. Collins (4) found an increase in size of seed the 
current year when a variety of maize from China was crossed with 
an American variety. Roberts (14) also reports a noticeable in- 
crease in size of hybrid seed over that from the pistillate parent when 
the Chinese variety of maize used by Collins was pollinated with 
pollen from an American dent variety, Pride of Saline. In order 
to obtain further information on the subject, Collins mixed pollen 
from two varieties of corn and applied it to the silks of one of the 
varieties, thus obtaining pure and hybrid seed on the same ear. The 
difference in size of seed produced could be readily noted, as CoUins 
says : 

The hybrid and pure seeds from each of the ears, when weighed separately, 
exhibited such striking differences that it is thought advisable to place the 
results on record. In every instance the hybrid seed was larger than the pure 
seed borne on the same ear, the increase ranging from 3 to 21 percent. 

Data from Professor Carrier's (3) experiment conducted at the 
Virginia station show that in all crosses the immediate effect was to 
increase the yield. When different strains of Boone County White 
were crossed there was an increase in yield of from 7.6 to 31.7 per- 
cent of crossed over uncrossed seed. The results of this experiment 
confirm those obtained by Collins. In this experiment, which was 
completed in the fall of 1914, pollen from two varieties of corn was 
mixed and used to pollinate the stigmas or silks of one of the varie- 
ties, as was done by Collins. In 37 crosses, 26 gave an increase in 
size of hybrid seed over pure seed, varying from 0.2 to 16.04 percent. 
In the II crosses where there was a decrease, the decrease ranged 
from 0.3 to 13.45 percent. The average percentage of increase in 
size was 5.93 percent ; of decrease, 5.65 percent. 

From the results of the experiments cited above it is advisable, in 
some cases at least, to cross different strains or varieties of corn 
to increase the yield. Owing to Mendelian splitting it can not be ex- 



it 



WOLKK: ICFFI-.CT OF CROSSINC VAKll.ril.:. < »l (ORN. 267 

pccted that the yield of hybrid corn will continue to increase in future 
generations. Therefore it is good practice to cross such corn every 
year for the next year's planting, — that is, i)rogeny from the same 
cross should not be used for more than one generation. 

Statement of the Problem. 

The purpose of the experiment here reported is to deierniinc the 
immediate effect of crossing varieties of corn on the size of seed 
produced and to ascertain whether this method of cross-pollination 
is advisable from a practical standpoint. Mixed pollen was used to 
pollinate each ear, so as to eliminate error as far as possible. 

Material and Methods Used. 

Eight varieties of corn were used in this work, namely, Collier's 
Excelsior, Casey's Purebred, Boone County Special, Columbian 
Beauty, Hickory King, Gold Standard, Improved Golden Dent, and 
Improved Learning. The first five are white dents and the last three 
yellow dents. Due to the dominance of yellow over white and 
double fertilization in maize, called xenia, when white corn is crossed 
with pollen from a yellow variety the yellow color appears the cur- 
rent year. Thus in each case when both white and yellow pollen is 
used, we can detect the crossed seed. In crossing yellow varieties 
with pollen from white varieties, at least in the case of some varieties, 
the yellow color is diluted and the kernels produced possess a paler 
color than those fertilized with pollen from a yellow variety. 

In making the crosses, paraffined manila paper bags were used for 
covering tassels and silks. The ears were bagged before or as soon 
as the silks appeared and the tassels were bagged before any of the 
pollen had ripened. The ears were pollinated when the silks were 
about three inches long and the pollination was repeated in one to 
three days. Each ear was pollinated with pollen from another plant 
of the same variety, as well as with pollen from the variety with which 
it was to be crossed, the pollen being mixed in application. The bags 
were left on the ears until all danger of natural pollination was over. 

Results of the Experiment. 

The crosses obtained, the number of pure and of hybrid kernels 
on each crossed ear, the average weights of the pure and the hybrid 
kernels from each ear, and the percentage of increase in weight from 
crossing are shown in Tables i and 2. Table i presents these data 



268 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

for the crosses in which the female parent was a white and the male 
parent a yellow variety, while in Table 2 similar data for the crosses 
of yellow female and white male parents are given. 

Table i. — Number and Average Weight of Pure and Hybrid Kernels Pro- 
duced from Various Crosses of Corn Varieties in Which a White Female and 
a Yellozv Male Parent Were Used, with the Percentage of Increase in Weight 
of the Hybrid Over the Pure Kernels. 



Ear Number. | ' 


Female Parent. 


Male Parent. 


Pure 
Kernels. 


Hybrid 
Kernels. 


Increase. 


Number. 


Average 
Weight. 


Number. 


Average 
Weight. 










Grams. 




Grams. 


Percent. 


I 


Hickory King 


Improved Leaming 


231 


0.492 


91 


0.505 


2.64 


2 


Do. 


Do. 


62 


•473 


245 


•546 


15^43 


3 


Do. 


Gold Standard 


300 


.495 


3 


.513 


3.63 


4 


Boone Co. Special 


Improved Leaming 


3 


.293 


484 


.340 


16.04 


5 


Do. 


Improved Golden Dent 


416 


.342 


108 


•357 


4.38 


6 


Do. 


Gold Standard 


20 


•450 


351 


.428 


- 5.14 


7 


Casey's Purebred 


Do. 


325 


•431 


24 


.381 


-13.12 


8 


Boone Co. Special 


Do. 


258 


•343 


196 


.367 


6.99 


9 


Casej^'s Purebred 


Do. 


171 


•376 


I 


•425 


13^03 


10 


Collier's Excelsior 


Do. 


169 


.400 


68 


•448 


12.00 


II 


Do. 


Do. 


163 


.460 


21 


.437 


- 5-26 


12 


Columbian Beauty 


Improved Leaming 


83 


.471 


219 


.502 


6.58 


13 


Hickory King 


Do. 


142 


• 582 


31 


•513 


-I3^45 


14 


Boone Co. Special 


Gold Standard 


219 


•478 


23 


•506 


5^85 


15 


Casey's Purebred 


Do. 


164 


•391 


115 


•437 


11.76 


16 


Hickory King 


Improved Leaming 


37 


•596 


250 


.649 


8.89 


17 


Collier's Excelsior 


Gold Standard 


15 


.291 


157 


•329 


13-05 



The evidence of crossing in the crosses recorded in Table i was 
clearly visible, as would be expected because of the dominance of 
yellow over white and of xenia in maize. In 13 of the 17 crosses 
the hybrid seeds were the larger, the increase varying from 2.64 to 
16.04 percent. In the 4 remaining cases, there was a decrease, this 
decrease varying from 5.14 to 13.45 percent. 

It will be seen in Table i that a variety may cause a decrease in size 
of seed in one case when used as a parent in a hybrid and in another 
instance the same variety may produce an increase. In 3 of the 4 
crosses in which there was a decrease in size of seed Gold Standard 
is the male parent, but in another cross where Gold Standard is used 
as the male parent, a large increase is produced. Such contradictory 
results are difficult to explain in the light of present knowledge. 

The evidence of crossing in the crosses recorded in Table 2 was 
shown by the yellow grains being capped with white or by being a 



\V(»M'i:: oi'' crossinc; vaki j-iti i;s oi-" conn. 



269 



paler yellow than the ])iire seed. In many crosses the ])iire and 
hybrid seed were diflicult to dislinj^nish, hut all douhlful seed were 
weii^hed with the hybrids. However, these results can not be relied 
upon to as great an extent as those in 'Table I. 

Taulk 2. — A'unibcr and .Ivcroijc Weight of I'lirc and Hybrid Kernels Pro- 
dueed from l^arious Crosses of Corn Varieties in Whieh a Yellow Female and 
a White Male Parent Were Used, with the Percentage of Increase in Weight 
of the Hybrid Over the Pure Kernels. 











Pure 


Hybrid 










Kernels. 


Kernels- 




g 

3 


Female Parent. 


Male Parent. 










Increase. 








E 


u oO 


E 


u oO 




w 






3 

^; 


<i 
















Grams. 




Grams. 


. Percent. 


18 


Gold Standard 


Hickory King 


32 


0.478 


388 


0.427 


— II .94 


19 


Do. 


Do. 


226 


.257 


487 


.277 


7.78 


20 


Do. 


Collier's Excelsior 


210 


.351 


342 


.344 


— 2.03 


21 


Imp. Golden Dent 


Do. 


228 


.346 


350 


.331 


- 4-53 


22 


Do. 


Do. 


76 


.413 


319 


.414 


.20 


23 


Improved Leaming 


Boone Co. Special 


421 


•364 


75 


.371 


1.92 


24 


Imp, Golden Dent 


Collier's Excelsior 


265 


.406 


127 


•399 


- 1^75 


25 


Do. 


Do. 


342 


.413 


23 


.420 


1.69 


26 


Gold Standard 


Casey's Purebred 


321 


.376 


54 


•375 


- .30 


27 


Improved Leaming 


Boone Co. Special 


32 


•444 


210 


•446 


•45 


28 


Do. 


Do. 


33 


•445 


217 


•427 


— 4.21 


29 


Do. 


Columbian Beauty 


50 


•431 


172 


•432 


.20 


30 


Do. 


Boone Co. Special 


89 


•455 


160 


•458 


•65 


31 


Imp. Golden Dent 


Collier's Excelsior 


15 


.444 


147 


•451 


1^57 


32 


Gold Standard 


Casey's Purebred 


87 


.424 


160 


•435 


2.59 


33 


Imp. Golden Dent 


Collier's Excelsior 


322 


.401 


25 


.404 


.70 


34 


Improved Leaming 


Boone Co. Special 


117 


•327 


no 


•339 


3.66 


35 


Do. 


Do. 


128 


.414 


244 


.417 


.70 


36 


Do. 


Casey's Purebred 


197 


•398 


19 


.432 


8.54 


37 


Do. 


Boone Co. Special 


117 


.488 


29 


•507 


3^89 



In 6 out of 20 crosses there is a decrease in size of seed varying 
from 0.3 to II. 9 percent. The increase in the remaining 14 crosses 
varies from 0.2 to 8.54 percent. In 7 instances, the difference in 
the size of the pure and hybrid seed is so small that we may say that 
crossing had no effect. In 8 crosses the hybrid seed are substantially 
increased in size, while in 5 there are rather large decreases. 

In Table 2, as in Table i, those varieties which show a decrease in 
size of seed in one place likewise give an increase in other crosses. 
Of the 7 crosses where there is a decrease in size of kernel, Gold 
Standard is the female parent in 3 and Collier's Excelsior is the male 
parent in 3. 



2/0 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Selective Pollination and Crowding Out of Seed. 

It might be thought that the increase in size of hybrid seed on the 
same ear with pure seed could be attributed to the stimulus given by 
cross-fertilization or to lack of development of the pure seed owing 
to close or self-fertilization. By this stimulation, the hybrid seed may 
be able to become fertilized more rapidly and then develop sooner 
and crowd out the pure seed. The above ideas were brought out by 
Collins (6) and evidence was obtained on the subject from results 
of an accidental cross. Concerning this cross Collins says : 

An ear of " Maryland White Dent " was, pollinated by a plant of the same 
variety. Seven days later, ... a plant belonging to a red variety with yellow 
endosperm was accidentally used as a source of the pollen . . . 

In the resulting ear the two kinds of seed were easily distinguished. The 
pure seeds resulting from the first pollination were pure white, while the hybrid 
seed resulting from the second pollination were yellow. Unlike the ears where 
mixed pollen was used, the two kinds of seed were not indiscriminately dis- 
tributed. 

The ear produced 212 white, or pure, seeds and 161 that were yellow, or 
hybrid. The average weight of the pure seed was 283 grams per 1,000. The 
average weight of the hybrid seed was 292.5 grams per 1,000, a difference of 
9.5 + 1.06 grams, or 3.4 percent. 

On ear No. 2, Hickory King by Improved Teaming, we obtained 
evidence of a similar nature. In this instance there was only one 
yellow grain in the last two inches at the tip, the others being un- 
crossed (pure white). The remainder of the ear showed hybrid seed 
with the exception of twelve grains. The hybrid seed averaged 0.546 
gram j)er seed, the pure seed at the tip 0.473 S'^^^^ those inter- 
mixed with crossed grains 0.475 gram per seed. The grains at the 
extreme tip were excluded since they are usually smaller than the 
other grains on the ear. 

A Plan for the Production of Pure and Hybrid Seed Corn. 

The results from experiments with first generation hybrids in corn 
and also those from investigations concerning the increased yield due 
to the immediate etTect of crossing corn show that in some instances 
cross pollination is profitable both to the farmer and seed grower. 
They may expect, in some crosses, sufficient increase in yield due to 
the immediate effect of crossing to pay for the extra expense of 
hybridization. Many experiments have shown that the increase in 
yield in the generation has been greater than that of the current 
year. If the crosses which give a sufficient increase in yield the cur- 



woi-i'i:: i-.Fi-i'.cr oi- cuossinc. vakiktiivS oi- corn. 



rent year also i;ivc an increase the following Near, the increase ob- 
tained the latter time is free of cost. 

By a system of planlinL^- two desired varit'lies in alternate rows and 
detasscling, it is easily possible to produce every year seed of tlic 
purebred varieties and at the same time their reciprocal hybrids. 
The details of such a plan, in dilTerent modifications, have been men- 
tioned by Williams (17), East (7), ShuU (16), and Collins (5), and 
need not be repeated here. 

In such a plan, different strains of the same variety may be used 
instead of distinct varieties. The former is probably more advisable, 
due to the fact that when strains are crossed the parents are not as 
diverse. The progeny will therefore remain more uniform and segre- 
gation of new characters will not take place to the same extent as 
when varieties are crossed. 

Conclusions. 

1. The beneficial effect due to crossing varieties in corn frequently 
appears in the current crop as well as in the first generation, being 
manifested in the increased weight of the hybrid seeds. In the 
crosses obtained, 56.8 percent produced profitable increases in yield 
(weight of kernels) and in 13.5 percent the increase was slight. In 
24.3 percent of the crosses, the decrease was marked, and in 5.4 
percent it was slight. The largest increase was 16.04 percent, and the 
greatest decrease 13.45 percent. 

2. The farmer or seed grower can make profitable application of 
these results by mixing seed at planting time. He may get not only 
an increase the current year but may obtain a larger one the follow- 
ing year. 

3. The increases and decreases are not confined to any certain 
varieties. However, Gold Standard and Collier's Excelsior gave de- 
creased kernel weights in a larger number of crosses than any of the 
other varieties used. 

4. All the crosses were made between distinct varieties and not 
between strains of the same variety. In a previous experiment at 
this station (3), larger increases in yield were obtained in the latter 
case than in this experiment. 

LITERATURE CITED. 

I. Beal, W. J. 

In Mich. Bd. Agr. Rpt. 1876, p. 206 ; 1877, p. 50; 1878, p. 450; 1880, p. 288; 
1881-2, p. 136. 



2/2 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

2. Belling, John. 

Hybrid Corn. Fla. Agr. Expt. Sta. Press Bui. 196. 1912. 

3. Carrier, Lyman. 

The Immediate Effect on Yield of Crossing Strains of Corn. Va. Agr. 
Expt. Sta. Bui. No. 202. 1913. 

4. Collins, G. N. 

A New Type of Indian Corn from China. U. S. Dept. Agr., Bur. Plant 
Indus. Bui. No. 161. 1909. 

5. • 

The Value of First-Generation Hybrids in Corn. U. S. Dept. Agr., Bur, 
Plant Indus. Bui. No. 191. 1910. 

6. AND Kempton, J. H. 

Effects of Cross-Pollination on the Size of Seed in Maize. In Miscel- 
laneous Papers, U. S. Dept. Agr., Bur. Plant Indus. Circ. 124. 1913. 

7. East, E. M. 

The Distinction between Development and Heredity in Inbreeding. In 
Amer. Nat., 43 : 178-179. 1909. 

8. . 

Heterozygosis in Evolution and in Plant Breeding. U. S. Dept. Agr., 
Bur. Plant Indus. Bui. No. 243. 1912. 

9. Hartley, C. P. 

The First Generation Cross No. 182. U. S. Dept. Agr., Bur. Plant Indus. 
Pub. No. 589. 191 1. 

10. , Brown, E. B., et al. 

Crossbreeding Corn. U. S. Dept. Agr., Bur. Plant Indus. Bui. No. 218. 
1912. 

11. Hayes, H. K., and East, E. M. 

Improvement in Corn. Conn. Agr. Expt. Sta. Bui. 168. 1911. 

12. McCluer, G. W. 

Corn Crossing. 111. Agr. Expt. Sta. Bui. 21. 1892. 

13. Morrow, G. E., and Gardner, F. D. 

Field Experiments with Corn. 111. Agr. Expt. Sta. Bui. 25. 1893. 

14. Roberts, H. F. 

First Generation Hybrids of American X Chinese Corn. In Ann. Rpt. 
Amer. Breeders' Assoc., 1911-12, vols. 7-8, p. 374. 1912. 

15. Sanborn, W. J. 

In Maine Bd. Agr. Rpt., 1889-90, p. 78. 1890. 

16. Shull, G. H. 

A Pure Line Method of Corn Breeding. In Ann. Rpt. Amer. Breeders' 
Assoc., 1909, 5 : 53-54. 1909. 

17. Williams, C. G. 

Corn Breeding and Registration. Ohio Agr. Expt. Sta. Circ. 66. 1907. 



TiiATc ii i:u : 1)i:vi;i.()1'mi:nt oi- 'nil', vviiicat ki:rni:l, 



^73 



THE PROGRESSIVE DEVELOPMENT OF THE WHEAT 
KERNEL— 11^ 

R. W. Thatcher, 
College of Agriculture, University of Minnesota, St. Paul, Minn. 

Introduction. 

At the meeting- of this Society held in Washington, D. C, Novem- 
ber, 1 91 3, I read a paper on this subject^ in which I presented the 
results of a series of analyses of Turkey and blucstem wheat cut at 
three-day intervals during the period of kernel formation. That 
paper contained a historical review of the investigations concerning 
the changes in chemical composition of the wheat kernel during its 
development and ripening and an explanation of the reasons for 
undertaking our ow^n work, which need not be repeated here. 

The results obtained in the first year of this investigation were so 
different than had been expected and opened so many interesting fields 
of inquiry that it was decided to continue the same, general method 
of investigation through another year, using a larger number of varie- 
ties of wheat, securing larger samples each time, and submitting them 
to somewhat more thorough examination than had been possible with 
the limited quantity of material which was available in the first year's 
samples. This was done, and the present paper is a report of the 
results of this work, the wheat having been grown and the samples 
secured in the summer of 1914, while the analytical work on the 
samples has been completed only recently. 

Experimental Data. 

Four plots were each seeded to a dift'erent variety of wheat to be 
used in this investigation. At blossoming time, however, it became 
apparent that the seed which had been used on one of the plots must 
have been very impure, as the crop was very badly mixed. This plot 
was, therefore, rejected, and only the other three used for the experi- 
mental work. The varieties grown on these three plots were of the 
fife, velvet chaff, ^ and bluestem groups, respectively. 

^ Presented at the eighth annual meeting of the American Society of Agron- 
omy, Berkeley, Cal., August 9, 1915. 

2 Thatcher, R. W., The Progressive Development of the Wheat Kernel, 
Jour. Amer. Soc. Agron., 5 : 203-213. 1913. 

3 The so-called " velvet chaff " wheat used in this experiment is a variety of 



274 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

The methods of tagging the heads at a uniform stage of develop- 
ment, of sampHng at intervals for analysis, and of drying and pre- 
paring the grain for analysis were the same as in the preceding year, 
except that approximately 2,400 heads of each variety were tagged 
and at each sampling a sufficient number of spikes to yield 100 grams 
or more of dry matter were taken. The velvet chaff was tagged on 
July 3, the fife on July 6, and the bluestem on July 7, these being 
the dates on which the particular variety showed the largest propor- 
tion of its spikes with the anthers of the two central spikelets pro- 
truding, the proper condition for tagging. The first sample from each 
variety was taken seven days after the tagging was done, and each 
successive sampling was done at three-day intervals, care being ob- 
served to take the samples at the same hour of the morning each day, 
so that the intervals were regular and exactly uniform. The yield 
and certain physical properties of the kernels from each sampling 
are shown in Table i. 



Table i. — Yield and Physical Properties of Kernels of Velvet Chaff, Fife and 
Bluestem Wheats Cut at Successive Stages of Development. 



Sample No. 


Date of Cutting. 


Average 
No. of 
Kernels per 
Spike. 


Weight of 

1,000 
Kernels. 


Dry Matter 
per 1,000 
Kernels. 


Specific 
Gravity of 
Kernels. 


Volume of 
1,000 
Kernels. 


Velvet Chaff: 






gm. 


gm. 




C.C. 


2873 


July II 


21. 1 


7-39 


6.92 


I.4175 


5.57 


2874 


July 14 


23-7 


10.73 


10.03 


1.4323 


7-49 


2875 


July 17 


23.6 


16.15 


14.88 


1-4344 


11.27 


2876 


July 20 


24-3 


18.79 


17.42 


1.4319 


13.12 


2877 


July 23 


25-4 


22.29 


20.50 


1.4302 


15.58 


2878 


July 26 


22.9 


23.75 


21.73 


1.4185 


16.74 


2879 


July 29 


24.1 


24.02 


22.25 


1.4147 


16.98 


Fife: 














2880 


July 14 


23-3 


6.34 


5.96 


1.4086 


4.50 


2881 


July 17 


21.9 


12.21 


11.34 


1.4266 


8.56 


2882 


July 20 


25.1 


14.41 


13.38 


1.4250 


10. II 


2883 


July 23 


24.7 


18.16 


16.61 


1.4234 


12.75 


2884 


July 26 


26.1 


19.42 


17.33 


1.4115 


13.76 


2885 


July 29 


24.4 


21.31 


19.62 


1.4090 


15.13 


2886 


Aug. I 


23.0 


21.24 


19.20 


1. 4109 


15.15 


Bluestem: 














2887 


July 15 


24.6 


6.98 


6.47 


1.4130 


4.94 


2888 


July 18 


24.4 


10.94 


10.17 


1.4367 


7.61 


2889 


July 21 


25.2 


15-85 


14.65 


1.4202 


11.22 


2890 


July 24 


23.4 


21.54 


19.85 


1.4107 


15.27 


2891 


July 27 


26.9 


23.29 


21.57 


1. 4102 


16.50 


2892 


July 30 


25.5 


26.02 


23.90 


1.4088 


18.47 


2893 


Aug. 2 


24.7 


27-95 


25.23 


1.4045 


19.91 



the group usually known by that name in Minnesota. It is a bearded, smooth- 
chaffed spring wheat belonging to the group of which the Preston is a typical 
variety. 



tiiatc'hI'R: i)KVi:r.op^ii:N r of tiiI': wiii:at Ki:uNi:r.. 275 

The average number of kernels per spike should have been the 
same in each successive samplinfj^ of the same variety if the spikes 
had been ideally uniform. The variations are not larc^e, however, 
and indicate a fair dcqrcc of uniformity in the spikes as sampled. 

Composition of tiik Dry Mattkr. 

The amount of dry matter per 1,000 kernels and the volume oc- 
cupied by T,ooo kernels naturally increases with each successive 
sampling. The increase is not regular, however, the gain in dry 
matter during some three-day periods being more than double that 
during other periods of the same length. There is absolutely no 
correlation between the amount of gain in dry matter per day and 
the stage of development, except that the most rapid gain was made 
during the first three-day interval by all three varieties. At subse- 
quent stages of development, rapid and slow accumulation of dry 
matter appear to alternate. This is probably due to variations in 
weather conditions. An attempt was made to correlate the rapidity 
of increase in dry matter with metereological data which had been 
taken in the same field by another division of the college. No satis- 
factory correlation could be found, perhaps because of the fact that 
the three-day intervals were not coincident in the case of all three 
varieties, or of the difficulty of finding any single meteorological 
factor which would represent the total influence of weather upon crop 
development. The amount of evaporation from a wick evaporimeter 
seemed to be likely, to represent most nearly the transpiration eflfect 
upon plants ; but no correlation of the data of this kind with the 
increase in dry matter of the wheat kernels during the same period 
could be found which seemed to be sufficiently close or consistent 
to justify its presentation here. The results of the analyses of the 
samples, calculated to the basis of moisture-free material, are shown 
in Table 2. 

Table 2 shows the same regular decrease in percentage of ash, 
ether extract, and crude fiber, the same fluctuations in the percentage 
of starch, and the same phenomenon of decreasing percentage of 
protein in the early stages followed by markedly increasing per- 
centages in the later stages of development, that were found last year. 
Since these phenomena are exhibited uniformly by each of the five 
successive series of samples of wheat which have been studied during 
the two years covered by these invstigations, it seems safe to conclude 
that they correctly represent the actual course of the changes in per- 
centage of these constituents during the development of wheat kernels 



2/6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

in Minnesota. The changes in percentage of protein in the dry matter 
are contrary to the general behef concerning the storage of larger 
proportions of starch during later periods of development, although 
a few observers have noted the same general tendency toward in- 
creased percentage of protein as the kernels approach maturity, as 
was noted in my former article. 



Table 2. — Analyses of Sample Kernels of Velvet Chaff, Fife, and Bluestem 
Wheats Cut at Successive Stages of Development. 









Percentage Composition of the Dry Matter. 


Sample No, 


Date of Cutting. 


Ash. 


Protein 


Ether 


Fiber. 


Total 


Starch. 


Undeter- 








(jVXs.y). 


Extract. 


Sugars.^ 




Velvet Chaff: 




















287^ 


July 


1 1 


2.77 


13.03 


4.96 


5,03 


12.54 


50.70 


10.97 






T /I 


2.62 


12.92 


4.36 


4.56 


4.88 


60.30 


10.36 




July 


17 


2.47 


12.63 


3.62 


4-51 


3-15 


62.53 


11.09 


2876 


July 


20 


2.43 


12.30 


3-35 


3-89 


2.33 


63-50 


12.20 


2877 


July 


23 


2.40 


12.70 


3-33 


3-66 


1-74 


64-45 


11.72 


2878 


July 


26 


2.44 


13-14 


3.00 


3-83 


1.48 


63-05 


13.06 


2879 


July 


29 


2.57 


13.29 


3-01 


3.53 


1.62 


63-05 


12.93 


Fife: 




















2880 


July 


14 


2.53 


13.89 


4.26 


5-14 


10.33 


51-85 


12.00 


2881 


July 


17 


2.40 


12.82 


3-93 


4.64 


5-27 


59-15 


11.79 


2882 


July 


20 


2.28 


12.64 


3.85 


4-30 


2.47 


61.79 


12.67 


2883 


July 


23 


2.28 


13-34 


3.62 


3-95 


1.94 


63-78 


11.09 


2884 


July 


26 


2.15 


13-41 


3-30 


3-78 


1.56 


63-70 


12.10 


2885 


July 


29 


2.30 


14.18 


3.22 


4.21 


1.36 


62.10 


12.63 


2886 


Aug. 


I 


2.31 


15-50 


3-13 


4.09 


1.29 


63.40 


10.28 


Bluestem: 




















2887 


July 


15 


2.94 


14.20 


5-39 


5-26 


9.08 


53-93 


9.20 


2888 


July 


18 


2.70 


13.00 


4.04 


4-33 


7.67 


54-84 


13.42 


2889 


July 


21 


2.42 


13.01 


3-28 


4.08 


3-13 


61.00 


13.08 


2890 


July 


24 


2.30 


13-91 


3.16 


4.29 


1-56 


63.42 


11.36 


2891 


July 


27 


2.05 


14.23 


3-16 


3.51 


1.38 


65.11 


10.56 


2892 


July 


30 


2.01 


14.77 


3.02 


3-83 


1.27 


64.82 


10.28 


2893 


Aug. 


2 


2.24 


15.62 


2.91 


3-40 


1.08 


65-50 


9.25 



1 Calculated as dextrose. 



Determinations of the total sugars, calculated a,s dextrose, were 
made on this year's samples. They show that the very immature 
kernels contain relatively large proportions of sugars, which decrease 
rapidly to less than 2 percent of the dry matter at the " milk " stage, 
and then decrease slightly but regularly until maturity. 

The summation of the constituents, as determined, leaves a fairly 
uniform percentage of "undetermined" material. This probably 
includes pentosans, and some hemicelluloses of the pericarp material 
of the kernels. So far as I am aware, there has been no systematic 
study of the nature of the materials which are not determined in the 



TiiATc-m:R: i)i:vKi:i)i'isiKN'r oi-^ riii-. vviii:.\r ki;um:i., 



277 



regular process of analyses of Ibis kind, hut which, in ordinary state- 
ments of proximate analysis fall in the group called " nitrogen-frcc 
extract " which is delerniincd hy difference. 'This is an interesting 
problem for future study, which might yield results of considerable 
theoretical and practical use. 

Wkicuts of Matkrtat.s tn thk Kkunkls. 

In Table 3. are shown the actual weights of materials present in a 
kernel of each of the varieties, at each successive stage of growth, as 
calculated from the percentage composition and the weight of dry 
matter per 1,000 kernels, as shown in Tal:)lcs i and 2. 



Table 3. — Weight in MiUigrams'i)f Material per Kernel of Velvet Chaff, Fife, 
and Bluestem Wheats Cut at Successive Stages of Development. 



Sample No. 


Date of 
Cutting. 


Weight per Kernel in Milligrams. 


Ash. 


Protein 
(N X 
5.7)- 


Ether 
Extract. 


Fiber. 


Total 
Sugars. 1 


Starch. 


Unde- 
ter- 
mined. 


Dry 
Matter 


Velvet Chaff: 




















2873 


July II 


.192 


.902 


-343 


.348 


.868 


3-508 


•759 


6.92 


2874 


July 14 


.263 


1.296 


•437 


•457 


•489 


6.048 


1.039 


10.03 


2875 


July 17 


.368 


1.879 


.539 


.671 


.468 


9-304 


1.650 


14.88 


2876 


July 20 


.423 


2.143 


•584 


.678 


.406 


11.062 


2.124 


17.42 


2877 


July 23 


.492 


2.603 


.683 


• 750 


•357 


13.212 


2.402 


20.50 


2878 


July 26 


.530 


2.855 


.652 


•832 


•321 


13-701 


2.838 


21.73 


2879 


July 29 


•572 


2-957 


.670 


.785 


•360 


14.028 


2.877 


22.25 


Fife: 




















2880 


July 14 


•151 


.828 


.254 


.306 


•615 


3.090 


•715 


5.96 


2881 


July 17 


.272 


I-4S4 


•445 


.526 


•598 


6.707 


1^337 


11-34 


2882 


July 20 


•305 


1. 691 


•515 


• 575 


•330 


8.267 


1.695 


13-38 


2883 


July 23 


•379 


2.149 


.601 


•656 


•322 


10-594 


1.908 


16.61 


2884 


July 26 


•383 


2.391 


• 588 


.674 


.278 


11.358 


2^157 


17^83 


2885 


July 29 


•451 


2.782 


.632 


.826 


.267 


12.184 


2.478 


19.62 


2886 


Aug. I 


•443 


2.976 


.601 


.785 


•247 


12.173 


1^973 


19.20 


Bluestem: 




















2887 


July 15 


.190 


.919 


.349 


•340 


• 587 


3-489 


•595 


6.47 


2888 


July 18 


•275 


1.322 


.411 


•440 


.780 


5-577 


1^365 


10.17 


2889 


July 21 


.354 


1.906 


.480 


• 598 


.458 


8.937 


1. 916 


14.65 


2890 


July 24 


.426 


2.761 


.627 


-851 


.310 


12.589 


2.285 


19.85 


2891 


July 27 


.442 


3-069 


.681 


•757 


.298 


14.044 


2.278 


21.57 


2892 


July 30 


.480 


3-530 


.722 


.915 


•303 


15.492 


2^457 


23.90 


2893 


Aug. 2 


•565 


3-941 


.734 


.858 


.272 


16.525 


2^334 


25.23 



^ Calculated as dextrose. 

The figures in Table 3 show that there was a regular increase in 
the quantity of all the constituents except the sugars, as the kernels 
developed. The increase in ether extract and fiber is relatively less 
than that in ash, protein and starch. This is as might be expected, 



278 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

since the ether extract is made up of the oil from the germ and the 
coloring matters of the pericarp and contains little material derived 
from the endosperm, and the fiber comes chiefly from the pericarp. 
Since the later stages of development consist almost exclusively of 
filling in of endosperm material, the reason for the observed varia- 
tions is obvious. 

The decrease in actual amount of sugars is undoubtedly due to the 
rapid conversion of the sugars which enter the seed into reserve 
starch. Presumably, all of the reserve carbohydrate material which 
enters the kernel does so in the form of sugars, which are then con- 
verted into starch by the endosperm cells. It is evident from these 
figures that the vegetative portions of the plant actually manufacture 
sugars and translocate them to the kernel faster than the endosperm 
cells are able to synthetize them into starch, in the earlier periods of 
kernel development, but that in later stages starch formation pro- 
ceeds at a relatively more rapid rate and the proportions of sugars 
are actually reduced. 

Daily Gain of Protein and Carbohydrates. 

In Table 4 are shown the actual quantities of protein and of carbo- 
hydrates gained by the kernels per day, during each of the successive 
intervals, and the ratios between these quantities. 

Most students of the problem of kernel development have believed 
that protein is elaborated relatively early in the plant's life and that 
the larger proportion of material which is first moved into the kernel 
is protein in character, while the latter filling in is chiefly with starch. 
Many authors state this as an established fact. Brenchley and Hall,* 
whose results were the immediate cause for the inauguration of our 
own work along this line, came to the conclusion that the material 
which the plant moves into the kernel is uniform in composition 
throughout the period of endosperm-filling. The results which we 
have obtained, on every one of the five series which have been studied, 
however, indicate that while the material which the kernel gains from 
day to day is richer in carbohydrates than the original " mold " 
into which it enters and continues to be so until about the "milk" 
stage, usually gaining a little in relative amount of carbohydrates 
before that stage, the ratio of carbohydrates to protein soon begins 
to fall ofif and continues to do so until maturity. It is evident, there- 
fore, that either the material moving into the kernels during later 
stages of development is richer in protein or that the carbohydrate 

4 Brenchley, W., and Hall, A. D., Jour. Agr. Sci., 3 : 195-217. 1909. 



Til Ale II i:r : i)i;vi;L()rM EN r oi- riii': wiii.A'r ki:uni:l 



2/9 



material i)icsont in the kernel is bein^e: destroyed l)y respiration i)roc- 
esses. The latter explanation was snjj^i^ested by Miss Hreneliley to 
account for tbe diniinisbed weiiibt of dry matter in tbe kernels wbieb 
is nearby always found in the last staii^es of kernel develoj)nient. It 
hardly seems possible, however, that this effect could be sufficient to 
account for the relative gain in protein which has been found in the 
later intervals in all of these series. 



Table 4. — Cain in Milligrams of Protein and Carbohydrates in Each Kernel 
of Velvet Chaff, Fife, and Bluestem Wheats per Day, with the Ratio 
of the Two Materials for Each Period. 





Gain in Milligrams per Day. 


Ratio of Carbohy- 


Period 


Protein. 


Carbohydrates. 


drates to Protein. 




Velvet Chaff: 








First Sample 7/1 1 


0.902 


5-483 


6.08 


7/11-7/14 


O.I3I 


0.850 


6.49 


7/14-7/17 


0.194 


1-353 


6.96 


7/17-7/20 


0.088 


0.726 


8.25 


7/20-7/23 


0.153 


0.827 


5-33 


7/23-7/26 


0.084 


0.324 


3.86 


7/26-7/29 


0.034 


0.119 


3-50 


Fife: 








First Sample 7/14 


0.828 


4.726 


5-71 


7/14-7/17 


0.209 


1. 481 


7.09 


7/17-7/20 


0.079 


0.566 


7.17 


7/20-7/23 


0.152 


0.871 


S-7I 


7/23-7/26 


0.081 


0.329 


4.07 


7/26-7/29 


0.130 


0.429 


3-29 


7/29-8/1 


0.068 


loss 




Bluestem: 








First Sample 7/15 


0.919 


5. oil 


5-8o 


7/15-7/18 


0.134 


1.050 


7.82 


7/18-7/21 


0.195 


1.249 


6.44 


7/21-7/24 


0.285 


1.365 


4.82 


7/24-7/27 


0.103 


0.457 


4.35 


7/27-7/30 


0.157 


0.597 


3-88 


7/30-8/2 


0.137 


0.274 


2.00 



Relation between Composition and Specific Gravity. 

After tabulating the data shown in Table 4, it was noticed that 
there was an apparent correlation between the carbohydrate-protein 
ratio of the material which entered the kernels and the specific gravity 
of the resultant kernels. Accordingly, these two sets of data were 
brought together and are presented in Table 5. 

It will be observed that, with only one significant exception, there 
is a definite correlation between the two sets of data in Table 5 for 
each series of samples. This affords both an interesting confirma- 



280 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



tion of the statements of Kornicke and Werner^ concerning the actual 
specific gravity of the carbohydrates and protein of the wheat kernel, 
and a useful check upon the accuracy of the different workers who 
accumulated the different analytical .figures from which these data 
were calculated. 



Table 5. — Relation between Composition of Material Gained by the Kernels 
and Their Specific Gravity. 



Period. 


Bluestem Wheat. 


Fife Wheat. 


Velvet Chaflf Wheat. 


Carbohy- 
drate-Pro- 
tein Ratio. 


Specific 
Gravity. 


'"arbohy- 
drate-Pro- 
tein Ratio. 


Specific 
Gravity. 


Carbohy- 
drate-Pro- 
tein Ratio. 


Specific 
Gravity. 


First sample 


5.80 


1. 4130 


5-71 


1.4086 • 


6.08 


I.4175 


First 3 days 


7.82 


1-4367 


7.09 


1.4266 


6.49 


1.4323 


Second 3 days 


6.44 


1.4202 


7.17 


1.4250 


6.96 


1-4344 


Third 3 days 


4.82 


1. 4107 


5-71 


1.4234 


8.25 


I -43 19 


Fourth 3 days 


4-35 


1. 4102 


4.07 


I.4II5 


5-33 


1.4302 


Fifth 3 days 


3-88 


1.4085 


3-29 


1.4090 


3-86 


I-4185 


Sixth 3 days 


2.00 


1.4045 


loss 


1. 4109 


3-50 


1-4147 



Character of the Nitrogen-containing Compounds. 

Table 6 presents the results of a study of the character of the 
nitrogen-containing compounds of the samples of bluestem wheat 
taken at successive stages of growth in this investigation, made by 
Mr. J. J. Willaman, one of the assistant chemists in our Division of 
Agricultural Chemistry. 



\ Table 6. — Character of the Nitrogen-Containing Compounds in Bluestem 
Wheat at Successive Stages of Grozvth. 





Stutzer's Separation. 


Hausmann's Fractions. 


Sample 












Mono- 
Amino 




No. 


Albuminoid 


Amid 


Amid 


Humin 


Basic 


Total 




Nitrogen. 


Nitrogen. 


Nitrogen. 


Nitrogen. 


Nitrogen. 


Nitrogen. 


Recovered. 




% 


% 


% 


% 


•% 


% 


% 


2887 


76.92 


23.08 


12.55 


13-54 


21.00 


54-31 


101.40 


2888 


85.28 


14.72 


13-03 


9.19 


19.49 


58.59 


100.30 


2889 


84.69 


15-31 


13-93 


8.55 


18.26 


57-56. 


98.30 


2890 


88.04 


11.96 


16.02 


7.86 


18.16 


58.08 


100.12 


2891 


88.32 


11.68 


17-25 


7-57 


18.22 


57.33 


100.37 


2892 


93-15 


6.85 


17.24 


7.76 


16.29 


58.46 


99-75 


2893 


94.09 


5-91 


16.31 


6.83 


16.69 


61.43 


101.26 



It has been known for a long time that the proportion of the 
nitrogen-containing compounds of any plant material which are pre- 
cipitated by Stutzer's reagent (cupric hydroxide) and which is com- 

^ Kornicke, F., and Werner, H., Handbuch des Getreidebaues. Berlin, 1884. 



Til ATt ii i:k : i)i:vi:i.()i'M I'.N'r (^i- tjii". vviii:.\'I' ki:kni:l, 



nionlv supposed to rcjucscMit tlu- coinpk'tcly synllu'li/.cd **;ill)U- 
minoids " as cHslini^uislicd from the soluhli' " aniidcs " wliicli arc not 
])recipitated by this rca.ncMit, increases as llie plant nialurc^. Tlu- 
proportion of " alhuniinoid " to "total" nitrogen has. therefore, 
come to he reqarded as an index of maturity of the material in (jues- 
tion. The hi^ures obtained by Willaman, by the use of the Stut/XT's 
se]\aration, on this set of samples would apjK'ar to confirm this 
opinion. Furthermore, his results from the acid-hydrolysis method 
of investioation offer an explanation for this change in composition. 
It has been shown by Osborne" that the individual proteins of wheat, 
when com])letely hydrolyzed, yield the following widely varying per- 
centages of "amid" or "ammonia" nitrogen: Gliadin, 24.5 percent^; 
glutenin, 18.8 percent; globulin, 7.7 percent; and albumin, 6.8 per- 
cent. Gliadin and glutenin are the characteristic endosperm proteins, 
which united together form the gluten of flour, which has been 
shown by Blish^ in some work just completed in our laboratory to 
yield on hydrolysis approximately 23 percent of its nitrogen as " amid 
nitrogen." Globulin and albumin, on the other hand, are character- 
istic pericarp and germ proteins. The regularly increasing per- 
centage of amid nitrogen found in the hydrolyzed proteins of these 
successive samples of bluestem wheat is, therefore, undoubtedly due 
to the increasing proportion of gluten-proteins, as the proportion of 
endosperm in the kernel increases. Similarly, it is probable that the 
increase of Stutzer's " albuminoid nitrogen " as plants approach 
maturity is due to the increase of reserve protein food material, as 
contrasted with vegetative or structural protein. 

The data presented in Table 6 clearly show a progressive increase 
in the proportion of highly organized reserve proteins of the endo- 
sperm during the successive stages of growth. 

Summary. 

The results of two seasons' investigations, including five separate 
series of successive samplings of the developing wheat kernel, clearly 
indicate the following changes in composition of the kernel, under 
Minnesota conditions : 

I. The percentage of material matter (ash), ether extract, and crude 

^ Osborne, T. B., The Protein of the Wheat Kernel, Carnegie Institution of 
Washington, D. C, Pub. No. 84, p. 14. 1907. 

Van Slyke's corrected figure for completely hydrolyzed gliadin is 25.5 per 
cent. We have confirmed this in our laboratory, and find that it agrees with 
the results from hydrolyzed gluten, reported by Blish. 

8 Blish, Morris J., Jour. Ind. and Eng. Chem., 7 (1915). In press. 



282 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

fiber in the dry matter progressively decreases. The percentage of 
sugars also decreases, but much more rapidly during the early stages 
of development than after the " milk " stage, from which time on the 
decrease is very slight. 

2. The percentage of protein in the dry matter decreases slightly 
until about the " milk " stage and then begins to increase, the final 
matured sample usually showing a higher percentage than the very 
immature ones. 

3. The actual quantity of all these materials in the kernels increases 
during each successive period of growth, with the exception of 
sugars, of which there is an actual decrease as the kernels develop, 
undoubtedly by reason of their conversion into reserve starch. 

4. The carbohydrate-protein ratio is at first greater and then 
diminishingly less in the developing kernels than in the " mold " or 
pericarp material into which the endosperm material is filled. 

5. The observed changes in composition of the entire kernel are 
due, in part at least, to changes in the relative proportions of endo- 
sperm, pericarp, and germ, these being parts of the kernel which 
possess entirely different functions, and correspondingly different 
chemical composition. 

Acknowledgments. 

The thanks of the writer are due and are hereby expressed to Mr. 
C. H. Bailey for assistance in the field work and for determinations 
of the physical properties of the kernels, to Miss Cornelia Kennedy 
for the determinations of carbohydrates in the several samples, and 
to Mr. J. J. Willaman for the use of his data concerning the nitrogen 
compounds of the several samples. 



LYNDE-UUl'KI-. 



OSMOSIS IN SOILS. 



ON OSMOSIS IN SOILS.' 

C. J. LyNDE and J. V. DUPRE, 

Macdonald Coi.lkc.k, QukiU'.c, Canada. 

The Purpose of tttis Work. 

The results given in previous papers^ indicate: (i) That clay sub- 
soil acts to a certain degree as a semipermeable mem])rane when pre- 
pared as described below; (2) that water moves through the soil 
from points at which the soil solution has a low salt content to points 
at which it has a high salt content. The purpose of the work herein 
described was to apply many different tests to these phenomena in 
order to gain new and, if possible, decisive evidence as to whether or 
not they are due to osmosis. Nine tests were made, which will be 
described in order. 

How THE Soil was Prepared. 

Unless otherwise stated, the soil as used in the 9 tests herein de- 
scribed was prepared as follows : 30 g. of moist clay subsoil was 
placed in a shaker bottle with 150 c.c. of distilled water and 10 drops 
of strong ammonia. It was shaken for two hours and then boiled 
gently for half an hour to expel the ammonia. This method of 
preparation was adopted after tests had been made to determine (i) 
whether the soil should be shaken with ammonia or without; (2) the 
minimum effective quantity of ammonia; (3) the minimum effective 
time of shaking and (4) whether the soil mud should be boiled to 
expel ammonia. In each test, duplicate tubes were set up as shown 
in figure 14 and the soil solution was allowed to rise in the measur- 
ing tubes until the maximum pressures had developed. 

It was found that (i) the pressures were greater when the soil had 

1 Read before the Royal Society of Canada, May 26, 1915. 

2 Lynde, C. J., Osmosis in Soils : Soils Act as Semi-Permeable Membranes, 
Proc. Amer. Soc. Agron., 4: 102-108. 1912. Also in Jour. Phys. Chem., 16: 
759. December, 1912. Lynde, C. J., and Bates, F. W., Further Studies in the 
Osmosis of Soils, Proc. Amer. Soc. Agron., 4: 108-121. 1912. Lynde, C. J., 
and Dupre, H. A., Osmosis in Soils: The Efficiency of the Soil Constituents 
as Semi-Permeable Membranes, Jour. Amer. Soc. Agron., 5 : 102-106. 1913. 
Also in Trans. Royal Soc. Canada, 3d series, 7 : 105. 1913. Lynde, C. J., and 
Dupre, H. A., On Osmosis in Soils, Jour. Amer. Soc. Agron., 7: 15-19- IQIS- 
Also in Trans. Royal Soc. Canada, 3d series, 8: 133. 1914. 



284 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



been shaken with ammonia than when it had been shaken without 
ammonia; (2) the minimum effective quantity of ammonia was 10 

drops with 30 g. of subsoil and 
ISO c.c. of water; (3) the mini- 
mum effective time of shaking 
was 2 hours ; and (4) greater 
pressures were obtained when the 
soil had been boiled to expel am- 
monia than when it had not been 
boiled. 

A mechanical analysis of the 
clay subsoil gave the following 
results : 



■/ieasuring _ Tube 



-i 



-Di5f//Jed Water 



Clay 68.8 percent 

Silt 19.3 percent 

Very fine sand 11.9 percent 

Fine sand 0.0 percent 

Coarse sand 0.0 percent 



Soil Solution 



Part of the clay consisted of ex- 
tremely fine particles which on 
Clay 2ubsoil long standing in water assumed a 
jelly-like appearance; that is, part 
.Cotton Cloth of the clay was colloidal in nature. 



How THE Apparatus was 
Arranged. 

Fig. 14. — Apparatus used in meas- , j • r: ^ 

. . . The apparatus used m the first, 

urmg osmotic pressure m sons m the 

first, third, and fourth tests. third, and fourth tests was ar- 

ranged as shown in figure 14; that 
used in the remaining tests was arranged as shown in figure 15, 
except in the last part of the ninth test. 

The soil mud from one shaker bottle was poured into two tubes, 
1.4 cm. inside diameter and 15-20 cm. long, closed at the lower end 
with one layer of cotton cloth. The tubes were placed in cups of the 
centrifuge and the cups were filled with water to the level of the 
mud in the tubes. The centrifuge was run at top speed for about 
half an hour to settle the soil. The liquid was decanted and more 
mud was added and settled. This was continued until the desired 
depth of soil was obtained. The centrifuge made 1,300 revolutions 
per minute and the middle of the soil columns when settled was 25 
cm. from the axis. 



LYNDlC-nUl'RK : OSMOSIS IN SOILS. 



285 



The li(iuicl left in the lubes after the last setllin^ was used as the 
soil solulion. The tu1)es were lilted with measuring tubes, 0.5-1 nun. 
inside diameter and 45 cm. lonj^, and were then rinsed in distilled 
water and plaeed in wide-mouthed bottles lillcd with distilled water. 
The water in the bottles was changed daily. 




' ■ ' I' ' ' 'I I ■ ' ' ' I ' " * n I ' 




I " "1 



/^easurin^ Tljbe 

Di5Tf 7/ed Warer 
•So// ^o/ut/on 

Oay <3uhsoil 
Cotton Cloth 



Fig. 15. — Apparatus used in measuring the flow produced in the second, fifth, 
sixth, seventh and eighth tests and the first part of the ninth test. 

When the apparatus w^as arranged as in figure 14, the bottles were 
kept full to the brim and the liquid in the measuring tubes at the 
start was made to coincide with the water level in the bottle. When 
the apparatus was arranged as shown in figure 15, the water level in 
the bottles was kept at all times 1.5-2 cm. below the horizontal part 
of the measuring tubes. This distance (marked H on figure 15) 
was greater than the capillary Hft of the measuring tubes. This was 
done to eliminate the flow which might be produced by the capillary 
Hft of the tubes. 

Experimental Work. 
The tests to which the soil .was subjected to determine whether or 
not the results stated in the first paragraph were due to osmosis will 
now be described in detail. 



Test i. Is the Final Pressure Constant Under Given Conditions? 

The theory on which we have been working is as follows : It is 
possible (i) that soils act as semipermeable membranes; and (2), 
that water moves through the soil by osmosis. 

If this theory is true and if we have tubes set up as in figure 14, 



286 JOURNAL OF THE AMERICAN SOCIETY OF AGl 



the final pressure produced should be the same, whe lution 

in the measuring tubes is started at the water level jwed to 

rise or is started at the top of the measuring tubes allowed to 
fall. This, on trial, proved to be the case. 

Four tubes were set up as in figure 14. The liqi ' n the four 

measuring tubes was started, first at zero ; next, at a \ ure of 42.4 

cm. of water ; and lastly, again at zero. The final ^/i _sures were 

obtained in each case in about two weeks, but the tubes /ere allowed 



to stand one week longer to make sure, 
in Table i. 



These pressures are shown 



Table i. — The Final Pressure, in Centimeters of Water, Obtained in Each 

Tube in Test i. 



Starting Point. 


Tube I. 


Tube 2. 


Tubes. 


Tube 4. 


Temperature. 




Cm. 


Cm. 


Cm. 


Cm. 


Degrees C. 





13.2 


12. 1 


9-7 


14.0 


15-8 


42.4 cm. 


13.8 


13-2 


9-5 


15.0 


17.2 





17.6 


16.0 


10.9 


15-7 


17.2 



Conclusion. — The final pressures are approximately constant. 

Test 2. Is a Flow Produced? 

If the soil does act to a certain degree as a semipermeable mem- 
brane and if the water does move through the soil toward a solution 
of higher salt content, then if the apparatus is arranged as in figure 
15, there should be a flow of the solution along the horizontal measur- 
ing tubes. Since, with the apparatus arranged in this way, the maxi- 
mum pressure can not be produced, the flow should continue as long 
as the solution in the tubes has a higher salt content than the water 
outside, unless the soil is altered by the passage of water through 
it, The results indicate that this is the case. 

The four tubes used in the first test were arranged as show n 
figure 15, the soil solutions being retained in the tubes. Daily ob- 
servations of the flow were made for a period of two months. At 
the end of that time the flow was nearly as strong as at the beginni-' 
The observations were discontinued because other tests had \ 
started to determine the duration of the flow. TaVe 2 gives 
average daily flow for the first five days and for the last five days 
the two months. 

Conclusions: (i) A flow is produced. 

(2) It promises to continue for a lon-^ time. 



r.VNDIC-DlIl'UK : OSMOSIS IN SOILS. 



287 



Tabmc 



-The. 



ily T'low in Linear Centimeters Keeorded in Test 2 at the 
■'Hinniny and at the End of Two Months. 



Tin 



At the 





Tube I. 


Tube 2. 


Tube 3. 


Tube 4. 




Cm. 


Cm. 


Cm. 


Cm. 




1. 10 


1.76 


0.88 


1.62 




0.92 


1.68 


0.90 


1.30 



Tk5 3. Is THE Movement Due to Colloidal Swelling? 

We have t.-ied to discover causes other than osmosis which might 
bring about this movement. It occurred to us that possibly the water 
does not move through the soil, but that the colloidal clay absorbs soil 
solution, swells, and thus produces a movement. This did not seem 
probable in the light of the results obtained in the first and second 
tests ; nevertheless we decided to investigate it as follows : 

Four tubes were set up in the usual way, except that solid rubber 
stoppers were inserted in the bottoms of the tubes in place of the 
layer of cotton cloth. Thus no movement of water through the soil 
could take place. If then any pressure developed it must be due, 
not to osmosis, but to some other cause such as colloidal swelling. 

The four tubes were started with a pressure about one-half that 
which might be expected if they were set up in the regular way. No 
increase in pressure occurred and, on the contrary, the liquid in the 
measuring tubes fell to zero in two weeks. The measurements are 
given in Table 3. 

Table 3. — The Pressures in Centimeters of Water at the Beginning and at the 

End of Test 3. 



Time. 


Tube I. 


Tube 2. 


Tube 3. 


Tube 4. 




Cm. 


Cm. 


Cm. 


Cm. 




6.8 


8.2 


7-4 


7-5 


At the end 


0.8 


-0.3 


— 2.0 


— 2.0 



'hen tubes are set up with cotton cloth in the regular way the 
mc. .mum pressure remains constant for months if the water is 
changed daily and if the temperature remains constant. 

^onchision. — Since in this test the pressure did not increase and 

gradually decrease, it seems clear that the cause of the usual 

ement is rot colloidal swelHng. 

Test 4. Can the Movement be Reversed? 

If the movement is brought about by osmosis, then it should be 
possible to reve 1 se it by placing the stronger solution outside the tube. 



288 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



This, on trial, proved to be the case. Two tubes were set up as in 
figure 14 with soil solution in the tubes. The following tests were 
made: (i) The tubes were placed in distilled water until some 
pressure had developed; (2) they were placed lin a soil solution 
stronger than the solution in the tubes and the pressures fell to zero ; 
(3) they were again placed in distilled water and the pressure de- 
veloped again. The measurements are recorded in Table 4. The 
electrical resistances at 20° C. were as follows : Of the solution in 
tube I, 1,600 ohms ; in tube 2, 1,700 ohms; of the strong soil solution, 
550 ohms ; of A^/50 KCl solution, 350 ohms. 



Table 4. — The Pressures in Linear Centimeters Recorded in Test 4. 





Tube I. 


Tube 2. 


Time. 




Cm. 


Cm. 


Days. 




4.8 


3-3 


5 




0. 


0. 


5 




7.5 


7.3 


8 



Conclusion. — The movement can be reversed and this agrees with 
the theory that it is produced by osmosis. 

Test 5. How Long Will the Flow Continue? 

To determine how long the flow would continue, two tubes were 
set up as shown in figure 15, and daily observations on the flow were 
made. The test was started on January 15, 191 5, and at this date, 

Table 5. — The Daily Flow in Linear Centimeters, the Total Flow to Date 
in Linear and in Cubic Centimeters, and the Total Flow to Date in Cubic 
Centimeters per Square Centimeter. 



Period, 


Tube I. 


Tube 2. 




I-I9 


0.94 




I-I4 


1.09 




1-35 


1.05 


Fourth 10 days 


1.21 


1.08 




83 


.90 






-97 




1.22 


.96 




I-I7 


.91 




1.31 


1. 13 




1.23 


0.93 






0.93 




1. 10 


0.88 




139-00 


117.70 






4-53 




3-43 cc. 


2.55 



LVNDIC-DUI'KI': : OSMOSIS IN SOILS. 



289 



May 15, 191 5, the averaj^e daily flow is almost as ^rcat as it was at 
the beginning'. Table 5 gives the average daily flow for caeh lo-day 
period, the total flow in e.e., and the total flow in c.c. per sfiuare 
centimeter of soil surface. 

Measurements of Tube i : Depth of soil, 6.5 cm.; inside diameter, 
1.4 cm.; area of cross-section, 1.54 sq. cm.; measuring tube, i linear 
centimeter — .038 c.c. ; electrical resistance of the solution, 2,700 ohms 
at 16° C. Measurements of Tube 2: Depth of soil, 6.6 cm.; inside 
diameter, 1.5 cm. ; area of cross-section, 1.77 sq. cm. ; measuring tube, 
I linear centimeter = .0385 c.c. ; electrical resistance of the solution, 
2,700 ohms at 16° C. Electrical resistance of N/^o KCl with the 
same plates, 380 ohms at 18° C. Electrical resistance of distilled 
water, 50,000 ohms. 

Conclusion. — It appears that the flow will continue for a long 
time. 

Test 6. Does the Flow Vary with Change of Temperature? 

If the flow is an osmotic phenomenon, an increase in temperature 
should cause an increase in flow for the following reasons: (i) The 
osmotic pressure of the soil solution would increase with increase of 
temperature; (2) the concentration of the soil solution would prob- 
ably increase with increase of temperature; (3) the viscosity of the 
water would be decreased with increase of temperature and thus it 
should move through the soil more rapidly. 

To determine how the flow varies with change of temperature, two 
tubes were set up as shown in figure 15, and the daily flow measured 
at room temperature in the laboratory and at higher temperatures in 
an electric oven. The oven could be regulated to within 1° C. The 
measurements are given in Tables 6 and 7. 



Table 6. — The Average Daily Flow in Linear Centimeters at Different Tem- 
peratures and the Viscosity of Water at These Temperatures. 



Temperature. 


Tube I. 


Tube 2. 


Duration. 


Viscosity of 
Water. 




Degrees C. 


Cm. 


Cm. 


Days. 




16.8 




3-35 


2.48 


16 


.01100 


35-0. . 




4-53 


2.17 


15 


.00720 


45-0. . 




6.95 


3.10 


II 


.00597 


55.0. . 




8.45 


5-65 


2h 


.00506 


17.3. • 




3.20 


2.55 


2\ 





Conclusions.- — (i) The rate of flow increases with increase of 
temperature. 

(2) The increase is roughly proportional to the increase in fluidity 
of the water and to the absolute temperature. 



290 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Table 7. — The Ratios of the Daily Flow and the Ratios of the Fluidity of 
Water at These Temperatures. 



Temperature. 


Tube I. 


Tube 2. 


Fluidity. 


- - ■? 
Degrees C. 


• 






16.8 


1. 00 


1. 00 


1. 00 


35-0 


1-35 


0.87 


1.50 


45-0 


2.07 


1.25 


1,80 


58.0 


2.52 


2.27 


2.17 



Test 7. How Does the Flow Vary with Changes in the Concentration 

OF THE Soil Solution? 

To determine this, two tubes were set up as in figure 15. The 
tubes were first filled with a strong soil solution and the flow meas- 
ured. The tubes were then emptied and filled with the soil solution 
diluted to one half, and the flow measured. This was continued 
until the solution had been diluted to one sixty- fourth of its first 
strength. The last experiment was made with distilled water in the 
tubes. The electrical resistance of the solution was taken before and 
after each experiment. The readings, corrected for changes in tem- 
perature during the flow, are recorded in Table 8. The electrical 
resistance of N/^o KCl at 23° C. was 350 ohms. 



Table 8. — The Flow in Linear Centimeters per Day and the Electrical Resist- 
ance in Ohms at the Beginning and the End of the Experiment. 



Solution. 


Tube I. 


Tube 2. 


Tem- 
















Electrical 




Electrical 




Electrical 


per- 


Strength. 


Resistance at 


Flow. 


Resistance at 


Flow. 


Resistance at 


ature. 


Beginning. 




End. 




End. 






Ohms. 


Cm. 


Ohms. 


Cm. 


Ohms. 


° C. 


I 


160 


3-7 


150 


4-7 


150 


21.3 


1/2 


295 


2.8 


255 


3-0 


200 


22.4 


1/4 




2.6 


530 


2.7 


540 


20.0 


1/8 


1,050 


2.2 


980 


2.3 


980 


18.6 


1/16 


1.950 


2.3 


1.875 


2.25 


1.875 


17.2 


1/32 


3.700 


2.45 


3,100 


2.25 


3.300 


19.7 


1/64 


6,200 


2.35 


5.700 


2.1 


5.500 


18.2 




25,000 


1.95 


7,000 


1.9 


7,000 


17.6 



Conclusions. — (i) The flow decreases with decrease in concentra- 
tion of the soil solution. 

(2) The resistance of the soil solutions is always less at the end 
of an experiment than at the beginning. This indicates that the 
water moves through the soil toward the solution and in so doing 
carries soluble salts from the soil to the solution. (In this con- 
nection it must be stated that the electrical resistances were taken near 
the top of the tubes in all cases except when distilled water was used. 



LYNDE-nUPRK : OSMOSIS IN SOILS. 



291 



111 this case it was {:\kcu near the Ijolloni of llu- I lad llic other 

resistances l)een taken at this point, it is |)r()l)al)U' that they would 
have been lower.) 

(3) At low concentrations the flow decreases very slowly with 
decreasing concentration and there is still a marked flow when dis- 
tilled water is used instead of soil solution. This is investigated in 
the eighth test. 

Test 8. Why is Tiikre a Flow when Disthxed Water is Used as the 

Solution ? 

It seemed remarkable that a flow should take place with distilled 
water inside and outside the tube. The explanation which occurred 
to us and which when tested seemed to be correct is as follows : The 
lower part of the distilled water in the tube which is in contact with 
the soil forms a soil solution and this solution on account of its 
density remains in contact with the soil. That part of the distilled 
water in the bottle which is in contact with the soil forms a solution 
and this solution, on account of its density, sinks to the bottom of the 
bottle and is replaced by fresh distilled water. Thus the liquid just 
above the soil is a soil solution and the liquid just beneath the soil 
is nearly pure distilled water, and the flow takes place from the 
water to the solution. 

To test this explanation, we filled the tubes used in the seventh 
test with fresh distilled water and placed them in small test tubes 
containing distilled water. The bottoms of the tubes were approxi- 
mately I mm. above the bottoms of the test tubes. Our reasoning 
was that if the solutions inside and outside the tube had the same 
concentration there would be no flow, but if they had different con- 
centrations, there would be a flow in the direction of the stronger 
solution. In the experiment the outside solutions became more con- 
centrated than the inside solutions and the flow was toward the 
outer solutions. The results are given in Table 9. 

It wall be noticed that the outer liquids had the greater concen- 
tration and that the flow was negative in each case. It will be 
noticed also that the inside liquids had much higher resistances in 



Table 9. — The Negative Flow in Each Tube in Linear Centimeters per Day 
and the Electrical Resistances of the Solutions in Ohms. 

Tube I. Tube 2. 

Flow per day — 0.15 cm. — 2.3 cm. 

Electrical resistance of inside solution 25,000 ohms. 55, 000 ohms. 

Electrical resistance of outside solution 18,000 ohms. 25,000 ohms. 



292 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



this test than when distilled water was used in the seventh test. This 
indicates that in the seventh test the water moved up and carried salts 
from the soil to the inside solutions, but in this test the water moved 
down through the soil and the soluble salts were carried from the 
soil to the outer solutions. 

Test 9. Does Clay Subsoil in its Natural Condition Act as an Imperfect 
Semipermeable Membrane ? 

In the former tests the subsoil has been settled in an artificial 
manner. The following experiments were made with the subsoil in 
a more natural condition. 

Part I. — The moist clay subsoil was broken into small lumps and 
was rammed into the bottom of tubes similar to those used above. 
Four such tubes were set up as in figure 15. Tube i was filled with 
a strong sugar solution (100 g. granulated sugar in 100 c.c. of water) ; 
tube 2 was filled with a saturated K2SO4 solution ; tube 3 was filled 
with a medium strong soil solution; and tube 4 was filled with dis- 
tilled water. 

In tube I (sugar solution) a flow started at once and still con- 
tinues (9 days). In tube 2 (K2SO4 solution) a negative flow took 
place for 4 days and since then the flow has been positive. In tube 3 
(soil solution) a negative flow occurred for 6 days, and since then 
the flow has been positive. In tube 4 (distilled water) a very strong 
negative flow occurred at first, but it is gradually decreasing. 

We believe that the negative flow was caused by absorption and we 
expect the distilled water tube to give a positive flow when the soil 
becomes saturated. Whether it will do so remains to be seen. 

Part 2. — Two tubes were prepared in the same way and filled with 
the strong sugar solution. Each was then fitted with an open arm 
mercury manometer- and placed in distilled water. Strong pressures 
have developed in each case. These are recorded in Table 10. 

Table 10. — The Pressures in Centimeters of Mercury and the Duration of the 
■ Experiments in Test g, Part 2, to Date. 

Pressure. Duration. 

Tube I 18.3 cm. of mercury 7 days 

Tube 2 7.7 cm. of mercury 4 days 

General Conclusion. 

The results herein reported show that, whatever the cause, water 
moves through clay subsoil from a weak soil solution toward a strong 
one. The results agree with the theory that this movement is caused 
by osmosis. 



AC.KONOM IC Al-KAIUS. 



AGRONOMIC AFFAIRS. 

NOTES AND NEWS. 

J. T. Barlow of the University of Missouri is now assistant in 
agronomy in the New Mexico college. 

B. H. Hunnicutt, a member of this Society, is director of the newly- 
organized Agricultural Society of Brazil. It is the intention of the 
organizers to form corn clubs throughout Brazil similar to those 
which have been so successful in this country. 

Frank S. Kedzie, head of the chemistry department at the Mich- 
igan Agricultural College since 1902 and a member of the faculty for 
35 years, became president of the college on September 16. He suc- 
ceeded Dr. J. L. Snyder, who has been made president emeritus. It 
is understood that Professor Kedzie will act as president only tem- 
porarily, pending the selection of a permanent president by the board. 

C. V. Ruzek, formerly assistant agronomist in the Arkansas col- 
lege, now holds a similar position in the Oregon college and station. 

Charles E. Thorne, president of this Society during the current 
year, was doubly honored at Berkeley, Cal., in August by being 
elected president of the Association of Agricultural Colleges and 
Experiment Stations and of the Society for the Promotion of Agri- 
cultural Science. 

The following appointments were effective at the Iowa State Col- 
lege at the beginning of the college year: Ross L. Bancroft of the 
University of Wyoming as assistant professor of soils ; H. W. John- 
son of Iowa State College as instructor in soils and assistant in soil 
bacteriology ; and F. S. Wilkins of the University of South Dakota 
and Roy Westley of Iowa State College as instructors in farm crops. 
Messrs. Bancroft, Johnson and Wilkins were engaged in graduate 
work at the Iowa college during 1914-15. 

Recent appointments in the department of agronomy in the Penn- 
sylvania State College include Richard A. Andree of the University 
of Wisconsin as instructor in agronomy and farm mechanics ; H. P. 
Cooper of Clemson College and R. W. Duck of the University of 
Missouri as assistants in agronomy ; D. C. Wimer as assistant in 
agronomy in charge of laboratory work in soils ; and E. O. Anderson 
of the Michigan Agricultural College as instructor in farm manage- 
ment. 



294 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Frank K. Cameron, for the past several years in charge of soil 
chemistry investigations in the Bureau of Soils, U. S. Department of 
Agriculture, resigned on November i to enter commercial work. 
The three lines of investigation formerly under his charge have now 
been separated, R. O. E. Davis having been placed in charge of soil 
physical investigations and E. C. Shorey, formerly connected with 
soil fertility investigations in the Bureau of Plant Industry, in charge 
of soil chemical investigations. The third line, that of investigations 
of fertilizer resources, has not yet been assigned. 

P. T. Meyers has been appointed assistant agronomist of the 
Wyoming station. 

J. B. Sieglinger has been appointed assistant agriculturist in the 
office of cereal investigations, U. S. Department of Agriculture, and 
assigned to grain-sorghum and broomcorn investigations at the Wood- 
ward, Okla., field station. 

The American Association for the Advancement of Science will 
hold its annual meeting during convocation week, December 27, 
1915, to January i, 1916, at Columbus, Ohio. The retiring vice- 
president for the Section of Agriculture, L. H. Bailey will deliver an 
address on the "Forthcoming Situation in Agricultural Work (Part 
II)." Another vice-presidential address of interest to agronomists is 
that of G. P. Clinton before the Section of Botany, " Botany in Rela- 
tion to American Agriculture." 

The Second Pan-American Scientific Congress will meet in Wash- 
ington, D. C, December 27, 191 5, to January 8, 1916. George M. 
Rommel, of the Bureau of Animal Industry, U. S. Department of 
Agriculture, is Chairman of Section III, Conservation of Natural 
Resources, Agriculture, Irrigation, and Forestry. Subsections of 
this Section are as follows: (I) Conservation of Mineral Resources, 
President C. R. Van Hise of the University of Wisconsin, chair- 
man; (II) Conservation of Forests, Henry S. Graves, Chief of the 
U. S. Forest Service, chairman; (III) Conservation of Water for 
Power, N. C. Grover of the U. S. Geological Survey, chairman; 
(IV) Irrigation, S. Fortier, Office of Public Roads and Rural Engi- 
neering, U. S. Department of Agriculture, chairman ; (V) Conserva- 
tion of the Animal Industry, Geo. M. Rommel, Bureau of Animal 
Industry, U. S. Department of Agriculture, chairman; (VI) Con- 
servation of the Plant Industry, David Fairchild, Bureau of Plant 
Industry, U. S. Department of Agriculture, chairman ; and (VII) 
Marketing and Distribution of Agricultural Products, Charles J. 
Brand, Chief, Office of Markets and Rural Organization, U. S. De- 
partment of Agriculture, chairman. 



ACiRONOMlC AFFAIRS. 



295 



REPORT OF THE SECRETARY FOR 1915. 

Tho work of llio year has few inarkt'd fi'adiri'.s. 'Tliosi.' of most interest are 
the steady increase in menihershii) of the vSociety and tiie more f^eneral ac- 
ceptance of the Journal as a medinm of puhhcation, as indicated l)y the in- 
crease in mannscripts suhmitted. This more al)nndant material has made 
possible the more prompt and ref>nlar issnance of the Journal. Incident to 
the increase in membership, the work of the Secretary has materially increased. 

It is a pleasure to record the efficient service rendered by Miss J. R. Taylor, 
the many valuable suggestions received from the former Secretary, Mr. C. R. 
Ball, and the general cooperation of the members of the Society. 

I. FUNDS COLLECTED BY THE SECRETARY. 

The following is a classified list of the funds which have been received by 
the Secretary, chiefly from dues of new members and the sale of the Proceed- 
ings and Journal. All these have been transmitted to the Treasurer and are 
included in his annual report. 

Classified Receipts and Disbursements, November i, 1914-JuLY 22, 1915. 

Receipts. 

To dues collected (itemized list appended) : 

8 new members for 1914 at $2.00 $ 16.00 

68 new members for 1915 at 2.00 136.00 

7 new members for 1915 at 1.50^ 10.50 

34 local members for 1915 at .50 17.00 $179.50 



To Proceedings and Journal sold : 



9 


copies 


of 


Volume 




. . .at $1.00 


$ 9.00 


3 


copies 


of 


Volume 




. , at 


2.00 


6.00 


II 


copies 


of 


Volume 


2 


at 


1. 00 


11.00 


5 


copies 


of 


Volume 


2 


, . .at 


2.00 


10.00 


II 


copies 


of 


Volume 


3 


at 


1. 00 


11.00 


7 


copies 


of 


Volume 


3 


. . ,at 


2.00 


14.00 


II 


copies 


of 


Volume 


4 


at 


1. 00 


11.00 


5 


copies 


of 


Volume 


4 


, ,at 


2.00 


10.00 


9 


copies 


of 


Volume 


5 


. ,at 


1. 00 


9.00 


5 


copies 


of 


Volume 


5 


at 


2.00 


10.00 


9 


copies 


of 


Volume 


6 


at 


1. 00 


9.00 


6 


copies 


of 


Volume 


6 


at 


2.00 


12.00 


5 


copies 


of 


Volume 


7 


, ,at 


1.702 


8.50 


6 


copies 


of 


Volume 


7 


at 


2.00 


12.00 


8 


single numbers of 


Volumes 5 and 6. . 






2.45 



$144.95 



$324.45 

1 Members of local sections who had previously paid dues of 50 cents each 
as local members. 

2 Sold through agent at 15 percent discount. 



296 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Disbursements. 



Dec. 2, 1914, by check to Treasurer Roberts $66.50 

March i, 1915, by check to Treasurer Roberts 84.45 

April I, 1915, by check to Treasurer Roberts 87.95 

July 22, 1915, by check to Treasurer Roberts 85.55 $324.45 

Balance on hand July 22, 191 5 $ 0.00 



2. MEETINGS. 

Two meetings have been held during the year, a special meeting of the Great 
Plains section and the present annual meeting. 

The special meeting was held at Mandan, N. Dak., in connection with the 
tenth annual meeting of the Great Plains Cooperative Association, on July 
14-16, 1915. There was no separation of the papers or programs of the two 
associations. About twenty-five papers were presented and about eighty per- 
sons attended the sessions. More than half those who presented papers and 
more than half those in attendance were members of the Society. For the 
first time, on joint invitation of the secretaries of the two organizations, the 
Canadian 'Department of Agriculture was officially represented. The repre- 
sentative. Dr. C. E. Saunders, Dominion cerealist, presented a paper at the 
meeting. 

The present assembly is the eighth annual meeting of the Society. There 
have been eight papers presented in our separate sessions and seven in joint 
sessions with the Society for the Promotion of Agricultural Science and the 
American Farm Management Association. Of the latter, two were by members 
of this Society. The average attendance at the sessions of this Society has 
been about forty and at the joint sessions about one hundred. 

3. LOCAL SECTIONS. 

The Society now has four local sections, located at Cornell University, Iowa 
State College, Kansas State Agricultural College and Washington, D. C. The 
Iowa section was organized during the year, with a membership of 28, of 
whom 19 are members of the general organization. The Washington section 
reports a local membership of 25, in addition to some 45 members of the gen- 
eral organization. All members of the Cornell University and Kansas sections 
are members of the Society. 

4. MEMBERSHIP. 

With each passing year, the membership of the Society steadily increases. 
It is a pleasure to record that a larger number of members has been added in 
191 5 than in any previous year. This has been without any special campaign, 
but is for the most part the result of individuals calling the attention of their 
coworkers to the Society. Many agronomic workers who are not members 
would, no doubt, be glad to join with us on request. If the plans of the Society 
are to be carried out, particularly as to increased frequency of issue of the 
Journal, a much larger number of members is necessary. 



AGRONOMIC AFFAIRS. 



297 



Changed Addressks. 



Of the 79 changes of adchi'ss recorded in the Journal during 1915, 51 were 
caused by changes of position. This nnniher is 11 percent of the total member- 
ship, as compared with 9 percent of similar clianges recorded in 1914. 

The folhnving is a complete list of those whose addresses are changed in the 
present issue : 



Bartlett, Harley H. 
Holland, Jens 
Brown, B. E. 
Burgess. P. S. 
Cory. Victor L. 
Crosby, M. A. 
Delwiche, E. J. 
Etheridge, W. C. 
Frear, D. W. 
Gaddis, P. L. 
Gaines, E. F. 



Garren, G. M. 
Goddard. L. H. 
Hanger. W. E. 
Hendrick. H. B. 
Kinney, H. B. 
Kinzy, Grover 
Krauss, F. G. 
Lathrop, Elbert C. 
Leth, Robert J. 
Miyake, Koji 
Pope, M. N. 



Reid, F. R. 
Schreiner, Oswald 
Sieglinger. J. B. 
Skinner, Joshua J. 
Suddath, R. O. 
Tucker, Geo. M, 
Voorhees, John H. 
Wentz, John B. 
Wermelskirchen, Louis 
Woodard, John 



New Members. 

The total membership at the end of 1914 was 397. To July 22, 81 new mem- 
bers have joined the Societ}^ During the same period 2 have died, 7 have 
resigned, and 24 have allow^ed their membership to lapse through nonpayment 
of dues. The total loss during the year is 33, leaving a net gain of 48 and a 
present membership of 445.^ Below is given a list of the new members for 
1915. Those marked with the asterisk have joined since the previous issue of 
the Journal. The addresses of all new members will be found in the address 
list of members which follows. 



Bailey, C. H. 
Bancroft, Ross L. 
Bassett, L. B. 
Benton, T. H. 
Beavers, J. C. 
Billings, G. A. 
Bledsoe, R. Page 
Bolland, Jens 
Brown, E. B. 
Burdick, R. T. 
Carnes, Homer M. 
Carter, L. M. 
Chapman, James E.* 
Cobb, J. Stanley* 
Cook, I. S., jr. 
Currey, Hiram M. 
Damon, S. C. 
Dean, H. K. 
Dorsey, Henry 
Ellison, A. D. 
Emerson, F. V. 
Forman, L. W. 



New Members for 1915. 

Gaddis, P. L. 
Galbraith, A. J. 
Garland, J. J. 
Gilbert, M. B. 
Hall, Thos. D. 
Hansen, Dan 
Hanson, H. P. 
Harper, J. D. 
Harrington, Oscar E. 
Head, A. F.* 
Hendry, Geo. W. 
Hill, H. H. 
Holland, Robert E. 
Hopkins. E. S.* 
Jensen, L. N. 
Jones, Earl* 
Jones, S. C. 
Kemp, W. B. 
Kenney, Ralph 
Kinney, H. B. 
Kinzy, Grover 
Knight, Chas. S.* 



Knutson, Geo. 
Krall, John A. 
Lechner, H. J. 
Leth, Robert J. 
Lohnis, F. 
Lora, Armando 
Luaces, Roberto 
Luckett, J. D.* 
McCall, M. C. 
Martin, J. H. 
Maughan, Howard J. 
Maxson, A. C. 
Merkle, Fred G. 
Miyake, Koji 
Moomaw, Leroy 
Neff, C. E. 
New, T. 
Noyes, H. A. 
Olsen, Jens. 
Olson, P. J. 
Osborn, L. W. 
Peterson, W. A. 



1 Since the above was written 26 more new members for 1915 have been 
received, making a total of 107 for the year, a net gain of 74 and a total present 
membership of 471. 



298 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Pieters, A. J. . 
Piper, Geo. 
Plummer, J. K. 
Potter, Ralph S. 
Powers, W. L.* 
Pritchard, Fred J. 
Reed, H. R. 
Reid, Harold W. 
Reinholt, Martin 
Rice, Thos. D. 
Richardson, A, M. 
Richey, F. D. 
Rudolph, E. G. 
Russel, J. C.* 



Ruzek, C. V * 
Scales, Freeman M. 
Schoth, Harry A * 
Scudder, H. D* 
Seamans, Arthur E. 
Shiffler, C. W* 
Simard, J. A. 
Simmons, Geo. E. 
Slipher, John A. 
Smith, Herbert G. 
Spafford, R. R. 
Stemple, F. W.* 
Stewart, Geo. 
Stoa, Theodore E. 



Thomas, Melvin 
Thompson, James 
Thysell, John C. 
Voigt, Edwin 
Walster, H. L. 
Watson, E. B. 
Welch, J. S. 
Wentz, John B. 
Westover, H. L. 
Will, Geo. F. 
Wright, R. Claude 
Young, M. H. 
Young, Y. 



Distribution of Membership. 



It is believed that a few figures on the distribution of the membership will 
be of interest. Of the 445 members of the Society, 413 reside within the conti- 
nental United States. Every State save two is represented by at least one 
member,^ and all except six have two or more members. The largest member- 
ship, quite naturally, is in the District of Columbia, the total there being 60. 
The States where the Society is represented by 10 or more members, with the 
number in each, are as follows: Kansas, 26; Illinois, 21; Iowa, 21; New York, 
20; California, 16; Texas, 16; North Dakota, 15; Georgia, 14; Ohio, 13; Indiana 
and South Dakota, 12 ; and Minnesota, Missouri, Utah and Wisconsin, 10 each. 
Five members reside in the insular United States — 3 in Hawaii and i each in 
the Philippines and Porto Rico. We have 16 members in Canada, 2 in Cuba, 
2 in Brazil, i in Mexico and i in Costa Rica, thus giving us a fair though very 
thin distribution throughout the Americas. With three members in Asia, i in 
Africa and i in Europe, every continent except Australasia is represented. 



Abbott, John B., Extension Div., College of Agr., Durham, N. H. 

Adams, E. L., U. S. Cereal Field Station, Biggs, Cal. 

Adams, Geo. E., State College, Kingston, R. I. 

Aicher, L. C, Aberdeen Substation, Aberdeen, Idaho. 

Allen, Edward R., Experiment Station, Wooster, Ohio. 

Allyn, Orr M., Experiment Station, Urbana, 111. 

Alway, F. J., Dept. Soils, University Farm, St. Paul, Minn. 

App, Frank, Rutgers College, New Brunswick, N. J. 

Arny, A. C, Dept. Agronomy, University Farm, St. Paul, Minn. 

Atkinson, Alfred, Experiment Station, Bozeman, Mont, 

Atwater, C. G., Agr. Dept., Am. Coal Prod. Co., 17 Battery PI., New York, N. Y. 
Ayrs, O. L., care Tenn. Coal, Iron & R. R. Co., Birmingham, Ala. 
Babcock, F. R., Williston Substation, Williston, N. Dak. 
Bailey, C. H., University Farm, St. Paul, Minn. 
. Ball, Carleton R., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Ball, Elmer D., Experiment Station, Logan, Utah. 

2 By the acquisition of a new member in one of these States and the removal 
of a member into the other, the Society on October 15 had at least one member 
in each of the 48 States. 



Address List of Members. 



AC.KONOMIC AI'IMIvS. 



299 



Ball. W ilhni- M., care K. D. P.all. Ks\A. Sla.. LoKaii, Utali. 

Ballard. Robert L., Cooprrative 1 )etiu)nstrali()ii Work, Aslibiirn, (ja. 

Bancroft. Ivoss L., Iowa State Collef^e, Anies, lovva. 

I^arker, Joseph F., Experiinent Station, (ieneva, N. \. 

Barre. II. W., Clemson College. Clemson, S. C. 

liartlett, JIarley H., Botanical Lab., Univ. of Mich.. Ann Arbor, Mich. 
Bassett. L. B., 2095 Dudk^ Ave.. St. Panl. Minn. 

Bear, Firman E., Agricultural College. Univ. of W. Va.. Morgaiitovvn, W. Va. 
Beaumont, A. B., 415 College Ave., Ithaca, N. Y. 
Beavers, J. C, Expt. Sta., La P^ayette, Ind. 

Bell, Henry G., Nat'l Fertilizer As.so.. Room 919 Postal Tel. Bldg., Chicago, 111. 

Bell, James M., Univ. of North Carolina, Chapel Hill, N. C. 

Bennett, Hugh H., Bur. Soils, U. S. Dept. Agr., Washington, D. C. 

Benton, T. H,, Iowa State College, Ames, Iowa. 

Bergh, Otto I., Experiment Station, Grand Rapids, Mich. 

Billings, G. A., Farm Management, U. S. Dept. Agr„ Washington, D. C. 

Bizzell, James A., Dept. Soil Tech., Cornell University, Ithaca, N. Y. 

Bledsoe, R. Page, Dept. Agron., Agr. College. Manhattan, Kans. 

Bolland, Jens, Pierpont, S. Dak. 

Bolley, H. L., Experiment Station, Agricultural College, N. Dak, 

Bonazzi, Augusto, Experiment Station, Wooster, Ohio. 

Bonnett, Robert K., Agricultural College, Manhattan, Kans. 

Boss, Andrew, Experiment Station, University Farm, St. Paul, Minn. 

Bouyoucos, G. J., Experiment Station, East Lansing, Mich. 

Boving, Paul A., Macdonald College, P. Q., Canada. 

Bower, H. J., Agricultural College, Manhattan, Kans. 

Bowman, Albert E., U. S. Office Farm Management, Laramie, Wyo. 

Bracken, John, Saskatchewan Univ., Saskatoon, Sask., Canada. 

Briggs, Lyman J., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Brodie, D. A., Farm Management, U. S. Dept. Agr., Washington, D. C. 

Brown, B. E., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Brown, C. B., Experiment Station, Garden City, Kans. 

Brown, E. B., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C 

Brown, P. E., Iowa State College, Ames, Iowa. 

Brunson, A. M., Experiment Station, Urbana, 111. 

Buchanan, John, Dept. Agron., Iowa State College, Ames, Iowa. 

Buckman, H. O., Dept. Soil Tech., Cornell University, Ithaca, N. Y. 

Buell, T. W., Experiment Substation, Krum, Texas. 

Bull, C. P., Experiment Station, University Farm, St. Paul, Minn. 

Burdick, R. T,, University of Vermont, Burlington, Vt. 

Burgess, James L., State Dept. of Agriculture, Raleigh, N. C. 

Burgess, P. S., Hawaiian Sugar Planters' Expt. Sta., Honolulu, Hawaii. 

Burnett, L. C, Dept. Agron., Iowa State College, Ames, Iowa. 

Burr, W. W., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Butler, Ormond R., Experiment Station, Durham, N. H. 

Call, L. E., Experiment Station, Manhattan, Kans. 

Cameron, Frank K., Bur. Soils, U. S. Dept. Agr., Washington, D. C. 

Cardon, P. V., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Carleton, M. A., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Carnes, Homer M., 728 14th St., Corvallis, Oregon. 



300 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Carr, Ralph H., 24 N. Salsbury Street, La Fayette, Ind. 

Carrier, Lyman, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Carroll, J. S., 1212 Empire Bldg., Atlanta, Ga. 

Carter, L. M., College of Agriculture, Athens, Ga. 

Cassel, Charles E., Tribune Substation, Tribune, Kans. 

Chambliss, Charles E., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Champlin, Manley, Experiment Station, Brookings, S. Dak. 

Chapman, Jas. E., Extension Dept., Univ. of Maine, Orono, Maine. 

Chappeiear, Geo. W., Miller Manual Labor School, Miller School, Va. 

Chilcott, E. F., Woodward Field Station, Woodward, Okla. 

Childs, R. R., College of Agriculture, Athens, Ga. 

Churchill, O. O., Dept. Agronomy, Agricultural College, N. Dak. 

Clark, Charles F., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Clark, Charles H., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Clark, J, Allen, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Clothier, R. W., Farm Management, U. S. Dept. Agr., Washington, D. C. 

Cobb, J. Stanley, Mass. Agr. College, Amherst, Mass. 

Coffey, G. N., University of Illinois, Urbana, 111. 

Cole, John S., care Forest Service, Majestic Bldg., Denver, Colo. 

Coleman, L. C, Director of Agriculture, Bangalore, Mysore State, India. 

Conn, H. J., State Experiment Station, Geneva, N. Y. 

Conner, A. B., Experiment Station, College Station, Tex. 

Conner, S. D., Dept. Chemistry, Purdue University, La Fayette, Ind. 

Cook, I. S., jr., College of Agriculture, Morgantown, W. Va. 

Cory, Victor L., R. R. No. 2, Krum, Tex. 

Cox, Joseph F., Agricultural College, East Lansing, Mich. 

Crabb, Geo. A., College of Agriculture, Athens, Ga. 

Craig, C. E., Escola du Ingenharia, Porto Alegre, Rio Grande do Sul, Brazil, S.A. 
Critz, Hugh, Starkville, Miss. 

Cromer, Otis, Experiment Station, La Fayette, Ind. 

Cron, A. B., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Crosby, M. A., 1120 Brown-Marx Bldg., Birmingham, Ala. 

Cunningham, C. C, Experiment Station, Manhattan, Kans. 

Currey, Hiram M., care C. S. Bowne, Aumsville, Oregon. 

Cutler, G. H., Saskatchewan University, Saskatoon, Sask., Canada. 

Damon, S. C, Experiment Station, Kingston, R. I. 

Davis, R. O. E., Bur. Soils, U. S. Dept. Agr., Washington, D. C. 

Davison, W., Dept. Agr., Charlottestown, P. E. I., Canada. 

Dean, H. K., Umatilla Expt. Farm, Hermiston, Oregon. 

Deatrick, Eugene P., 708 E. Seneca St., Ithaca, N. Y. 

Delwiche, E. J., 1221 Chicago St., Green Bay, Wis. 

Derr, H. B., Agricultural Advisor, Sikeston, Mo. 

DeTurk, Ernest, Experiment Station, State College, Pa. 

Dickenson, Robert W., Experiment Station, Urbana, 111. 

Dillman, A. C, Experiment Farm, Newell, S. Dak. 

Dobbs, W. Frank, Am. Coal Products Co., Athens, Ga. 

Donaldson, N. C, Judith Basin Substation, Moccasin, Mont. 

Doneghue, R. C, Agricultural College, N. Dak. 

Dorsey, Henry, College of Agriculture, Morgantown, W. Va. 

Douglass, 'T. R., Iowa State College, Ames, Iowa. 



AGRONOMIC A 1- FA IKS. 



301 



Diip.uar, J. F., Experiment Station, Anhnni, Ala. 

Dunlon. Leila, Aj^ricultnral ("oIIoko, Manliatlan, Kaiis. 

Dynes, O. W., N. Y. State ColleRe of A^v., Itliaca, N. Y. 

Eastman, J. P., State Seliool of Agriculture, Morrisville, N. Y. 

Ellett, W. B., Experiment Station, lUacksburK, Va. 

Ellison, A. D., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Emerson, F. V., 715 Boyd Ave., Baton Rouge, La. 

Engle, C. C, College of Agriculture, New Brunswick, N. J. 

Etheridge, W. C, Universit}'' of Florida, Gainesville, Fla. 

Evans, A. R., Exiierimcnt Station, Columbia, Mo. 

Evans, M. W., Forage-Crop Breeding Station, New London, Oiiio. 

Ewing, E. C, Scott, Miss. 

Fain, John R., College of Agriculture, Athens, Ga. 

Farrell, F. D., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Ferguson, A. M., Sherman, Tex. 

Fippin, E. O., Dept. Soil Tech., Experiment Station, Ithaca, N. Y. 

Fisher, M. L., Dept. Agron., Purdue University, La Fayette, Ind. 

Fitz, L. A., Agricultural College, Manhattan, Kans. 

Fletcher, S. W., 10 Pine St., Takoma Park, D. C. 

Foord, James A., Agricultural College, Amherst, Mass. 

Forman, L. W., Iowa State College, Ames, Iowa. 

Fraps, G. S., Experiment Station, College Station, Tex. 

Frear, D. W., Experiment Station, Agricultural College, N. Dak. 

Fred, Edwin Brown, College of Agriculture, Madison, Wis. 

Free, E. E., 1105 Madison Ave., Baltimore, Md. 

Gaddis, P. L., University Farm, Lincoln, Nebr. 

Gaines, E. F., Experiment Station, Pullman, Wash. 

Galbraith, A. J., Agricultural College, Guelph, Ont, Canada. 

Gardner, F. D., Experiment Station, State College, Pa. 

Garland, J. J., Agronomy Bldg., Madison, Wis. 

Garren, G. M., Experiment Station, College Station, Tex. 

Garver, Samuel, Forage-Crop Field Station, Redfield, S. Dak. 

Gentle, G. E., Experiment Station, Urbana, 111. 

Gericke, W. F., Experiment Station, Berkeley, Cal. 

Gernert, W. B., College of Agriculture, Urbana, 111. 

Getty, Robert E., Branch Experiment Station, Hays, Kans. 

Gilbert, Arthur W., Dept. Plant Breeding, Cornell University, Ithaca, N. Y. 

Gilbert, M. B., 406 South 15th St., Corvallis, Oregon. 

Gile, Philip L., Experiment Station, Mayaguez, Porto Rico. 

Gilmore, John W., College of Agriculture, Berkeley, Cal. 

Goddard, L. H., States Relations Service, U. S. Dept. Agr., Washington, D. C. 

Grace, O. J., Akron Experiment Farm, Akron, Colo. 

Grant, C. J., 64 Euclid Ave., Springfield, Mass. 

Grantham, A. E., Experiment Station, Newark, Del. 

Grantham, Geo. M., Experiment Station, East Lansing, Mich, 

Grimes, W. E., Agricultural College, Manhattan, Kans. 

Giiell, Aurelio R., Sah Jose, Costa Rica, C. A. 

Gustafson, A. F., Dept. Soil Tech., Univ. of Illinois, Urbana, 111. 

Hackleman, J. C, Experiment Station, Columbia, Mo. 

Hall, Thos. D., 201 Bryant Ave., Ithaca, N. Y. 



302 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Hallsted, A. L., Branch Experiment Station, Hays, Kans. 
Hanger, W. E, Townshend Hall, O. S. U., Columbus, Ohio. 
Hansen, Dan, Experiment Farm, Huntley, Mont. 
Hanson, H. P., Old Agrl. Hall, Iowa State College, Ames, Iowa. 
Hardenburg, E. V., Dept. Farm Crops, College of Agr., Ithaca, N. Y. 
Harper, J. D., Purdue University, West La Fayette, Ind. 
Harrington, Oscar E., Experiment Station, East Lansing, Mich. 
Harris, F. S., Experiment Station, Logan, Utah. 

Hartley, C. P., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Hartwell, Burt L., Experiment Station, Kingston, R. I. 

Haskell, S. B., Experiment Station, Amherst, Mass. 

Hastings, S. H., U. S. Experiment Farm, San Antonio, Tex. 

Hayes, Herbert K., Experiment Station, University Farm, St. Paul, Minn. 

Head, A. F., Dept. Agron., O. S. U., Columbus, Ohio. 

Hechler, W. R., Div. Farm Crops, Iowa State College, Ames, Iowa. 

Hendrick, H. B., States Relations Service, U. S. Dept. Agr., Washington, D. C. 

Hendry, Geo. W., College of Agriculture, Berkeley, Cal. 

Hershberger, Jos. P., jr.. College of Agriculture, Columbus, Ohio. 

Hill, H. H., Experiment Station, Blacksburg, Va. 

Holland, Robt. E., University Farm, Lincoln, Nebr. 

Holt, S. v., Experiment Station, Urbana, 111. 

Holtz, Henry F., Experiment Station, Pullman, Wash. 

Hopkins, Cyril G., Dept. Agronomy, Univ. of Illinois, Urbana, 111. 

Hopkins, E. S., Vermilion, Alberta, Canada. 

Hopt, Erwin, University Farm, Lincoln, Nebr. 

Hudelson, R. R., Experiment Station, Columbia, Mo. 

Hughes, H. D., Div. Farm Crops, Iowa State College, Ames, Iowa. 

Humbert, Eugene P., Experiment Station, State College, N. Mex. 

Hume, A. N., Dept. Agronomy, State College, Brookings, S. Dak. 

Hungerford, De F., College of Agriculture, Fayetteville, Ark. 

Hunnicutt, B. H., Escola Agricola de Lavras, Lavras, E. de Minas, Brazil, S. A. 

Hutchinson, W. L., Experiment Station, Clemson College, S. C. 

Hutchison, C. B., Univ. of Missouri, Columbia, Mo. 

Hutchison, Geo. S., care Albert Dickinson Co., Chicago, 111. 

Hutton, J. G., Dept. Agronomy, State College, Brookings, S. Dak. 

Hyslop, Geo. R., Agricultural College, Corvallis, Oregon. 

Israelsen, Orson W., University Farm, Davis, Cal. 

Jardine, W. M., Experiment Station, Manhattan, Kans. 

Jenkins, J. Mitchell, Rice Experiment Farm, Crowley, La. 

Jensen, L. N., Cereal Field Station, Amarillo, Tex. 

Johnson, F. W., Agricultural College, Manhattan, Kans. 

Jones, Earl, Mass. Agricultural College, Amherst, Mass. 

Jones, J. W., Nephi Substation, Nephi, Utah. 

Jones, S. C, Experiment Station, La Fayette, Ind. 

Kaden, F. C, College of Agriculture, O. S. U., Columbus, Ohio. 

Karraker, P. E., Agricultural College, Lexington, Ky. 

Keim, Frank D., University Farm, Lincoln, Nebr. 

Kellerman, Karl F., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Kelley, W. P., Citrus Experiment Station, Riverside, Cal. 
Kemp, W. B., College of Agriculture, Morgantown, W. Va. 



ACROXO.M IC Al'l' \l K'S. 



Kcnnard. F. L.. Northwest Siihslal loii, C looksloii, Miiiii. 

Konnoy. Ivalpli. Dept. Aj^ron.. Af^riciiltiiral College, iVhiiiliattaii, Kans. 

Keyser, Alviii, Experiment Station. I'"orl Collins, Colo. 

Khankhoje, P. S.. Wardlia, C. P.. Jndia. 

KicUler, A. F., AKrieultnral Collej^e, Baton Ronjjje. La. 

Kiessclbach, T. A., h^xperinient Station, Lincoln, Nebr. 

Kilpore, B. W., Experiment Station, Raleigh, N. C. 

Kinnaird. R. A., Normal School, Maryville, Mo. 

Kinne3^ E. J., Experiment Station, Lexington, Ky. 

Kimiey, H. B.. Black foot. Idaho. 

Kinzy, Grover, Centcrville, Md. 

Klein, Millard A., College of Agr., Univ. of Cal., Berkeley, Cal. 

Klinck, L. S., University of British Columbia, Victoria, B. C, Canada. 

Knight, C. S., University of Nevada, Reno, Nev. 

Knutson, Geo., care Great Western Sugar Co., Longmont, Colo, 

Koeber, James, University Farm, Davis, Cal. 

Krall, J. A., Iowa State College, Ames, Iowa. 

Krauss, F. G., Supt. of Extension Work, Haiku, Hawaii. 

Krechov, Wm., Agr. College, Nicolaevsky-Gorodok, Saratovsky Govt, Russia. 

Krusekopf, H. H., Agricultural Building, Columbia, Mo. 

Lathrop, Elbert C, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

La Tourette, Lyman D., Experiment Station, Manhattan, Kans. 

Laude, Hilmer H., Texas Substation No. 4, R. R. No. i, Beaumont, Tex. 

Lechner, H. J., Wash. State Normal School, Ellensburg, Wash. 

LeClair, C. A., Agricultural Building, Univ. of Missouri, Columbia, Mo. 

LeClerc, J. A., Bur. Chem., U. S. Dept. Agr., Washington, D. C 

Leidigh, A. H., Experiment Station, College Station, Tex. 

Leighty, C. E., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Leth, Robert J., Farm Management Dept., Iowa State College, Ames, Iowa. 

Lipman, C. B., Experiment Station, Berkeley, Cal. 

Lipman, Jacob G., Experiment Station, New Brunswick, N. J. 

Livingston, George, Office of Markets, U. S. Dept. Agr., Washington, D. C. 

Lloyd, E. R., Agricultural College, Miss. 

Lods, E. A., Demonstrator, Cowansville, Quebec, Canada. 

Lohnis, F., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Long, David D., State College of Agriculture, Athens, Ga. 

Loomis, Howard, Dept. Agronomy, State College, Brookings, S. Dak. 

Lora, Armando, Aguiar 47, Havana, Cuba. 

Loughridge, R. H., Univ. of California, Berkeley, Cal. 

Love, H. H., Dept. Plant Breeding, Cornell Univ., Ithaca, N. Y. 

Lowry, Marion W., College of Agriculture, Athens, Ga. 

Luaces, Roberto, Director, Gran j a Escuela, Camagiiey, Cuba. 

Luckett, J. D., 403 Asher St., La Fayette, Ind. 

Lumbrick, Arthur, The Epps Farms, Metcalf, 111. 

Lynde, C. J., Macdonald College, P. Q., Canada. 

Lyon, T. Lyttleton, Dept. Soil Tech., Cornell Univ., Ithaca, N. Y. 

McCall, A. G., Dept. of Agronomy, Ohio State Univ., Columbus, Ohio. 

McCall, M. C, Lind, Wash. 

McClelland, C. K., Experiment Station, Experiment, Ga. 
McFetridge, Wm. L., R. R. 4, Oshkosh, Wis. 



304 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



McHenry, Norris, R. R. 20, Elizabethtown, Ind. 
Mclntire, W. H., Experiment Station, Knoxville, Tenn. 
McKee, C^^de, Iowa State College, Ames, Iowa. 

McKee, Roland, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

McMurdo, Geo. A., Experiment Farm, Akron, Colo, 

McNeely, L. R., State College, New Mexico. 

Macfarlane, Wallace, Gogorza, via Park City, Utah. 

Mackie, W. W., 1358 Scenic Ave., Berkeley, Cal. 

Madson, B. A., University Farm, Davis, Cal. 

Martin, John H., Belle Fourche Expt. Farm, Newell, S. Dak. 

Maughan, Howard J., Experiment Station, Logan, Utah. 

Maxson, A. C, care Great Western Sugar Co., Longmont, Colo. 

Merkle, Fred G., R. 3, Box 8, Agricultural College, Amherst, Mass. 

Millar, C. E., Dept. Agron., Agricultural College, Manhattan, Kans. 

Miller, Edwin C, Dept. Botany, Agricultural College, Manhattan, Kans. 

Miller, M. F., Experiment Station, Columbia, Mo. 

Miyake, Koji, care Mrs. Good, 2212 Channing Way, Berkeley, Cal. 

Montgomery, E. G., Dept. Farm Crops, College of Agriculture, Ithaca, N. Y. 

Mooers, Charles A., Experiment Station, Knoxville, Tenn. 

Moomaw, Leroy, Judith Basin Substation, Moccasin, Mont. 

Moore, R. A., Univ. of Wisconsin, Madison, Wis. 

Moorhouse, L. A., Farm Management, U. S. Dept. Agr., Washington, D. C. 

Morgan, G. W., R. F. D., Huntley, Mont. 

Morgan, J. O., Agricultural College, College Station, Tex, 

Morrison, J, D., Experiment Substation, Highmore, S. Dak. 

Morse, Fred W., Experiment Station, Amherst, Mass. 

Morse, W. J., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Mosher, M. L., Clinton Co. Commercial Club, Clinton, Iowa. 

Mosier, J. G., Dept. Soils, Experiment Station, Urbana, 111. 

Musback, F. L., Eau Claire, Wis. 

Myer, D. S., Experiment Station, Lexington, Ky. 

Myers, C. H., Dept. Plant Breeding, College of Agriculture, Ithaca, N. Y. 

Nash, C. W., PubHc Schools, Carrington, N. Dak. 

Neff, C. E., 1312 Bass Ave., Columbia, Mo. 

Nelson, Martin, Experiment Station, Fayetteville, Ark. 

New, T., 218 Delaware Ave., Ithaca, N, Y, 

Newman, C. L., College of Agriculture, West Raleigh, N, C. 

Newman, L. H., Canadian Bldg., Ottawa, Canada. 

Newton, Robert, Woodstock, N. B., Canada. 

Noyes, H. A., Purdue Agr. Expt. Sta., La Fayette, Ind. 

Oakland, Irwin, 319 W. loth St., Sioux Falls, S. Dak. 

Oakley, R. A., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Olsen, Jens, 239 North 8th St., Corvallis, Oregon. 

Olson, George A., Experiment Station, Pullman, Wash, 

Olson, M. E., Soils Section, Iowa State College, Ames, Iowa. 

Olson, P, J., University Farm, St. Paul, Minn. 

Orton, W, A., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Osborn, L. W., Experiment Station, Fayetteville, Ark, 
Packard, Walter E,, Imperial Valley Station, El Centro, Cal. 
Pammel, L. H., Experiment Station, Ames, Iowa. 



AGRONOMrC AFFAIRS. 



Patterson, II. J., Agricultural CollrRc, CoIIikc Park, Md. 

Peacock, Walter M., Dept. Farm Crops, C'oIIcrc of Agr., Ithaca, N. Y. 

Peters, David C, The Christian Church, Honolulu, Hawaii. 

Peterson, W. A.. Northern Great Plains I'ield Station, Mandan, N. Dak. 

Pieters, A. J., 340 Blair Road, Takoma Park, D. C. 

Piper, C. v., Bur. Plant Indus., U. S. Dept. Agr., Washinulon. I). C. 

Piper, Geo. E., Glendive, Mont. 

Plummer, J. K., Experiment Station, Raleigh, N. C. 

Pope, M. N., 1482 Taylor Ave.. St. Paul, Minn. 

Potter, Ralph S.. Iowa State College, Ames, Iowa. 

Powers, W. L., Experiment Station, Corvallis, Oregon. 

Pridmore, J. C, Dept. Agronomy, College of Agriculture, Knoxville, Tenn. 
Pritchard, Fred J., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Rast, Loy E., College of Agriculture, Athens, Ga. 
Raymond, L. C, Macdonald College, P. Q., Canada. 
Reed, H. R., Yuma Field Station, Bard, Cal. 

Reid, F. R., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Reid, Harold W., Iowa State College, Ames, Iowa. 

Reinholt, Martin, Agricultural College, N. Dak. 

Rice, Thos. D., Bureau Soils, U. S. Dept. Agr., Washington, D. C. 

Richardson, A. M., Waterville, Wash. 

Richey, F. D., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Robb, Newell S., Dept. Agronomy, Idaho Univ., Moscow, Idaho. 

Robbins, F. E., 217 Waldron St., West La Fayette, Ind. 

Robert, J, C, Agricultural College, Miss. 

Roberts, George, Experiment Station, Lexington, Ky. 

Roberts, H. F,, Experiment Station, Manhattan, Kans. 

Roberts, John M., 345 West Michigan St., Chicago, 111. 

Robertson, A. D., Douglas, Ariz. 

Ross, John F., Cereal Field Station, Amarillo, Tex. 

Rothgeb, iB. E., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Rudolph, E. G., care The Dakota Farmer, Aberdeen, S. Dak. 
Russel, J. C, McPherson College, McPherson, Kans. 
Ruzek, C. v.. Experiment Station, Corvallis, Oregon. 
Salmon, Cecil, Experiment Station, Manhattan, Kans. 

Scales, Freeman M., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Schafer, E. G., Experiment Station, Pullman, Wash. 

Schmitz, Nickolas, Agricultural College, College Park, Md. 

Schoonover, Warren R., Experiment Station, Urbana, 111. 

Schoth, Harry A., Experiment Station, Corvallis, Oregon. 

Schreiner, Oswald, Bur. Plant Indus., U. S. Dept. Agr., Washington, D^ C. 

Schutz, H. H., Southwestern Irrigation Land & Power Co., Los Lunas, N. M. 

Scofield, C. S., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C 

Scudder, H. D., Experiment Station, Corvallis, Oregon, 

Seamans, Arthur E., Akron Experiment Farm, Akron, Colo. 

Shantz, H. L., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Shaw, Chas. F., Experiment Station, Berkeley, Cal. 

Shepperd, J. H., Experiment Station, Agricultural College, N. Dak. 

Sherwin, M. E., College of Agriculture, West Raleigh, N. C. 

Shififler, C. W., Dept. of Agronomy, Ohio State Univ., Columbus, Ohio. 



306 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



Shoesmith, V. M., Experiment Station, East Lansing, Mich. 

Shutt, Frank T., Central Experiment Farms, Ottawa, Canada. 

Sieglinger, J. B., Woodward Field Station, Woodward, Okla. 

Simard, J. A., Box 211, Quebec City, Quebec, Canada. 

Simmons, Geo. E., Dept. Agron., University of Maine, Orono, Maine. 

Skinner, Joshua J., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Slate, W. L., jr.. Agricultural College, Storrs, Conn. 

Slipher, John A., Purdue University, La Fayette, Ind. 

Sloan, Samuel L., Dept. Agronomy, State College, Brookings, S. Dak. 

Smith, Herbert G., Experiment Farm, Tucumcari, N. Mex. 

Smith, L. H., College of Agriculture, Urbana, 111. 

Smith, Ralph W., Dickinson Substation, Dickinson, N, Dak. 

Smith, Raymond S., Dept. Agronomy, State College, Pa. 

Snyder, Harry, 1800 Summit Ave., Minneapolis, Minn. 

Southwick, Benj. G., Experiment Station, Storrs, Conn. 

Southwick, Everett F., Bureau of Agriculture, Manila, P. I. 

Spafford, R. R., University Farm, Lincoln, Nebr. 

Spillman, W. J., Farm Management, U. S. Dept. Agr., Washington, D, C. 
Spragg, F. A., Experiment Station, East Lansing, Mich. 
Squires, J. H., Technical Division, Dupont Powder Co., Wilmington, Del. 
Stanton, T. R., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 
Starr, S. H., College of Agriculture, Athens, Ga. 

Stemple, F. W., Dept. Farm Crops, Ohio State Univ., Columbus, Ohio. 

Stevenson, W. H., Experiment Station, Ames, Iowa. 

Stewart, George, Dept. Agron., Agricultural College, Logan, Utah. 

Stewart, Robert, University of Illinois, Urbana, 111. 

Stoa, Theodore E., Agricultural College, N. Dak. 

Stockberger, W. W., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Stoddart, Chas. W., Dept. Chem., State College, Pa. 

Stone, J. L., Dept. Farm Crops, Cornell Univ., Ithaca, N. Y. 

Suddath, R. O., Suches, Union Co., Ga. 

Summerby, R., Macdonald College, P. Q., Canada. 

Sweet, Carl, Sherbrooke, P. Q., Canada. 

Tafif, P. C, Iowa State College, Ames, Iowa. 

Taliaferro, W. T. L., Agricultural College, College Park, Md. 

Taylor, F. W., Experiment Station, Durham, N. H. 

Thatcher, R. W., Dept. Agr. Chemistry, University Farm, St. Paul, Minn. 

Thomas, Melvin, Agricultural College, N. Dak. 

Thompson, G. E., Agricultural College, Manhattan, Kans. 

Thompson, James, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Thorne' Chas. E., Experiment Station, Wooster, Ohio. 

Throckmorton, R. I., Dept. Agronomy, Agricultural College, Manhattan, Kans. 
Thysell, John C, Dickinson Substation, Dickinson, N. Dak. 
Tinsley, J. D., 507 Union Station, Galveston, Tex. 
Tracy, S. M., Biloxi, Miss. 

Tucker, Geo. M., States Relations Service, U. S. Dept. Agr., Washington, D. C. 
Turlington, J. E., Farm Life School, Vanceboro, N. C. 
Tuttle, H. Foley, Experiment Station, Wooster, Ohio. 

Umberger, H. J. C, Extension Div., Agricultural College, Manhattan, Kans. 
Van Alstine, Ernest, 912 Nevada St., Urbana, 111. 



ACIKONOM IC M'l'AIKS. 



Vcilch. \\ P., Riir. Clicm., U. S. Dept. Aki ., VVashin^-toii, D. C. 

Vinall. Harry N.. Bur. Plant Indus.. U. S. Dept. A^'r., Washington, D. C. 

VoiKt. I'^dwin, 20 Waldron St., West La l\'iyette. Tnd. 

Voorliees, John II.. Franklin l-'arnis, ATendhani, N. J. 

Waldron. L. R., Dickinson Substation, Dickinson, N. Dak. 

Wallace, R. C. E., Purdue University, La Fayette, Ind. 

Walster, H. L., College of Agriculture, Madison, Wis. 

Warburton, C. W., Bur. Plant Indus.. U. S. Dept. Agr., Washington, D. C. 

Wascher, F. M. W.. Experiment Station, Urbana, 111. 

Watson, E. B., 17 Budd Hall, Univ. of Cal.. Berkeley, Cal. 

Wehrle, L. P., Agricultural College, Manhattan, Kans. 

Welch, J. S., Gooding Expt. Station, Gooding, Idaho. 

Welton, F. A., Experiment Station, Wooster, Ohio, 

Wentz, John B., N. Y. State College of Agr., Ithaca, N. Y. 

Wernielskirchen, Louis, Experiment Station, College Station, Tex. 

Westbrook, E. C, College of Agriculture, Athens, Ga. 

Westgate, J. M., Hawaii Experiment Station, Honolulu, Hawaii. 

Westover, H. L., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Wheeler, Clark S., 255 West Tenth St., Columbus, Ohio. 

Wheeler, H. C, 1018 W. Oregon St., Urbana, 111. 

Wheeler, H. J., Service Bureau, Am. Agr. Chem. Co., Boston, Mass. 

Wheeler, W. A.. Dakota Improved Seed Co., Mitchell, S. Dak. 

Whitcomb, W. O., Agricultural College, Bozeman, Mont. 

White, J. W., State College, Pa. 

Whiting, Albert L., 504 E. Chalmers St., Champaign, 111. 
Whitson, A. R., Dept. Soils, Univ. of Wisconsin, Madison, Wis. 
Wiancko, A. T., Experiment Station, La Fayette, Ind. 
Widtsoe, John A., Agricultural College, Logan, Utah. 
Will, Geo. F., Bismarck, N. Dak. 

Willej'-, Leroy D., Cheyenne Field Station, Archer, Wyo, 

Williams, Chas. Burgess, Experiment Station, West Raleigh, N. C. 

WilHams, C. G., Experiment Station, Wooster, Ohio. 

Willier, J. G., Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Wilson, Bruce S., Experiment Station, Manhattan, Kans. 

Winsor, L. M., Experiment Station, Logan, Utah. 

Winters, R. Y., Experiment Station, West Raleigh, N. C. 

Wood, Caspar A., Agricultural College, College Station, Tex. 

Wood, M. W., Boise, Idaho. 

Woodard, John, 11 West 29th St., Baltimore, Md. 

Woods, A. F., Experiment Station, University Farm, St. Paul, Minn. 

Woodworth, C. M., Agricultural Hall, Univ. of Wisconsin, Madison, Wis. 

Worrall, Lloyd, Barberton, Transvaal, South Africa. 

Worsham, W. A., jr.. State College of Agriculture, Athens, Ga. 

Worthen, E. L., Experiment Station, State College, Pa. 

Wright, Chas. Shannon, Campbell Soup Farm, Riverton, N. J. 

Wright, R. Claude, Bur. Plant Indus., U. S. Dept. Agr., Washington, D. C. 

Wyatt, F. A., 708 S. 4th' St., Champaign, 111. 

Yoder, Malon, 310 Worcester Bldg., Portland, Oreg. 

Yoder, P. A., Cairo, Ga. 

Young, M. H., Agricultural College, College Station, Tex. 



308 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY 



Young, Yungyen, Nanyang Middle School, Shanghai, China. 
Youngblood, Bonney, Experiment Station, College Station, Tex. 
Zavitz, C. A., Ontario Agr. College, Guelph, Ont, Canada. 
Zerban, F. W., 903 Whitney Central Bank Bldg., New Orleans, La. 
Zook, L. L., North Platte Substation, North Platte, Nebr. 

5. JOURNAL AND PROCEEDINGS. 

During the past year, as in 1914, the Journal has been issued bimonthly. 
The greater volume of material received for pubHcation has made possible the 
more prompt and regular issuance of the numbers, though there is still some- 
thing to be desired along this line. At the present time, four numbers have 
been issued and rather more than enough material is in hand for another with- 
out drawing at all on the papers presented at this meeting or at Mandan. 
Three possibilities for the future present themselves : To refuse publication to 
some papers which are well worth publishing; to increase the size of the bi- 
monthly issues from 48 to 64 pages; and to increase the frequency of issue. 
At the present time the most feasible plan seems to be to increase the size of 
the Journal, when enough papers are in hand, from 48 to 64 pages, and it is 
believed that the present condition of the treasury will justify this expense. 
Our ultimate aim should be a monthly publication of at least 48 pages, but at 
present neither the available material or the size of our membership justifies 
such a publication. The increased recognition of the Journal as a means of 
presenting material to the agronomic world is gratifying, and there seems to 
be little doubt that it will be even more generally used as we are able to 
increase the promptness and regularity of issuance. 

Disposal of Publications. 

In Table i will be found full data on the disposal of Proceedings and Jour- 
nal during the period from November i, 1914, to July 22, 1915. 



Table i. — Data Showing the Original Edition of Each Volume of the Pro- 
ceedings and Journal, the Distribution Made Previous to and During igi5, and 
the Number of Copies Remaining in Stock. 



Edition Printed, Disposition 
of Copies, and Number 
Remaining. 


Volumes. 


I 


2 


3 


4 


5 


6 


7 . 


Edition printed 

Previously accounted for . . 
Distributed to members, 

1915 

Distributed to subscribers, 

1915- • • 

Sold, 1915 


501 

337 
12 


517 

341 
16 


516 

368 
18 


514 

380 
16 


750 

606 
14 


750 

481 


750 

445 

41 
32 
13 


Total copies distributed . . . 


349 


357 


386 


396 


620 


496 


531 


Difference 

Sold on credit orders 


152 


160 


130 
I 


118 
I 


130 
I 


254 
I 


219 
2 




152 


160 


129 


117 


129 


253 


217 



AGRONOMIC AFFAIRS. 



The fijjTures sliow a healthy sale of all volumes, without special attention 
heinj? given to the matter. This source of income is practically all profit to 
tlie Society, as each volunu* is paid for out of cinrcMt funds, 'i'he average 
number of copies of cacli volume sohl was 15. A considerable part of these 
copies were sold to members who desiicd to complcle their set of publications 
of the Society. The income obtained from this source will be used in better- 
ing the Journal and in hastening the day when monthly issuance is possible. 

6. MINUTES OF THE ANNUAL MEETING. 
Berkeley, Cal., August 9-10, 1915. 
First Session, Monday Afternoon, August g. 

The meeting was called to order at 2 p.m. by President Thorne and the 
presentation of papers on the regular program was taken up, as follows : 

1. The Progressive Development of the Wheat Kernel (illustrated), by Dr 
R. W. Thatcher. 

2. Smut Explosions and Fires Occurring during Thrashing in the Wheat 
Fields in Eastern Washington, by Prof. E. G. Schafer (read by the Secretary 
in the absence of the author). 

3. Formation and Classification of the Soils of Arid Regions, by Prof. Chas. 
F. Shaw. 

The reading of the papers being concluded, President Thorne announced two 
special committees as follows : 

Nominating Committee. 
W. M. Jardine, chairman; R. W. Thatcher and J. W. Gilmore. 

Auditing Committee. 
E. L. Adams, chairman, and Geo. R. Hyslop. 

After announcements by Mr. C. G. Atwater regarding certain exhibits at the 
P. P. I. E., and by Secretary Warburton regarding applicants for membership, 
the payment of dues, handing in papers for editing, and the next session, the 
sessions adjourned. 

Second Session, Monday Evening, August 9. 

This session was held jointly with the Society for the Promotion of Agri- 
cultural Science and the American Farm Management Association for the 
presentation of the presidential addresses of the three organizations. It was 
called to order by President Raymond A. Pearson of Iowa State College, with 
about 200 persons present. The following papers were presented : 

The Foundation of a Rural Civilization, by Dr. H. J. Waters, President oi 
the Society for the Promotion of Agricultural Science. 

The Work of the American Agronomist, by Dr. Charles E. Thorne, Presi- 
dent of the American Society for Agronomy. 

What the Future Holds in Farm Management, by Prof. Andrew Boss, Presi- 
dent of the American Farm Management Association (read by Mr. B. H. 
Crocheron in the absence of President Boss). 



3IO JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



After announcements regarding the next sessions of the various organiza- 
tions, the joint session adjourned. 

Third Session, Tuesday Morning, August lo. 

The session was called to order by President Thorne at 9 a.m. The reading 
of papers was resumed, as follows : 

4. A Critique of the Hypothesis of the Lime-Magnesia Ration, by Dr. C. B. 
Lipman. 

5. State-wide Crop Improvement, by Mr. J. F. Cox. 

6. Relation of Type of Farming to Soil Fertility (illustrated), by Mr. D. A. 
Brodie. 

7. Experimental Methods and Results with Vetch in Oregon, by Prof. Geo. 
R. Hyslop. 

8. Refined Methods of Varietal Testing, by Mr. Frank A. Spragg (read by 
Mr. J. F. Cox in the absence of the author) . 

After the reading of Mr. Cox's paper the Society adjourned for a brief 
period to meet in joint session with the Society for the Promotion of Agri- 
cultural Science to listen to an address, " The Trend of Modern Agricultural 
Practice," by Dr. I. P. Roberts. 

The business session followed the reading of Mr. Spragg's paper. 

{Business Session.) 

On motion, the minutes of the last annual meeting as printed in the Journal 
(6: 276-278) for November-December, 1914, were approved. 

The report of the Secretary was read and, on motion, approved. 

The report of the Treasurer was read and, on motion, accepted. 

The report of the Auditing Committee was read by the chairman, Mr. Adams, 
and was approved, on motion. 

The report of the Executive Committee was read by the Secretary and, on 
motion, was approved. 

In lieu of a report from the Committee on Soil Classification and Mapping, 
a letter from the chairman, Dr. G. N. Coffey, was read by the Secretary. After 
remarks by Mr. E. B. Watson approving the suggestions of Dr. Coffey, the 
report was, on motion, adopted. The suggestion of the chairman with regard 
to the reduction of the size of the committee was left in the hands of the 
Executive Committee, with power to act. 

The report of the Committee on Agronomic Terminology, in the absence of 
the chairman and members, was read by the Secretary and, on motion, accepted. 

A letter from Prof. C. V. Piper, chairman of the Committee on the Stand- 
ardization of Field Experiments, stating that the committee had no report to 
make, was read by the Secretary. 

The report of the Committee on Varietal Nomenclature, in the absence of 
the chairman, Prof. E. G. Montgomery, was read by the Secretary and, on 
motion, adopted. 

The Nominating Committee reported the following nominations for officers 
of the Society for the year 1916 : 

President, Mr. C. R. Ball, U. S. Dept. of Agriculture. 

First Vice-President, Prof. Alfred Atkinson, Montana Expt. Station. 

Second Vice-President, Prof. A. N. Hume, South Dakota Expt. Station. 



AGRONO]\riC Al'FAlKS. 



Secretary. Mr. C. W. Warburtoii, U. S. Dept. of Agriculture. 
Treasurer, Prof. George K()l)crts, Kentucky ICxpt. Station. 
On motion, the Secretary was instructed to cast the ballot of the Society for 
the nominees and, this being done, they were declared elected to the respective 
offices. 

A communication from Secretary of State W. J. Uryan inviting the Society 
to participate in the Second Pan-American Congress, to be held at Washington, 
D. C, December 27, 1915, to January 6, 1916, was read by the Secretary. On 
motion, the newly elected president, Mr. C. R. Ball, was named as delegate of 
the Society to this Congress, and the Secretary, Mr. C. W. Warburton, as 
alternate. 

On motion, the Society expressed its thanks to Dean Thomas F. Hunt and 
the faculty of the college of agriculture of the University of California for the 
hospitality extended during its meeting. 

The Society then adjourned to meet at 2 p.m. 

Fourth Session, Tuesday Afternoon, August 10. 

This session was held jointly with the Society for the Promotion of Agri- 
cultural Science and the American Farm Management Association. It was 
called to order at 2 p.m. by Dr. Charles E. Thorne, President of the American 
Society of Agronomy. The following papers were presented : 

The Eflfect of Time of Seeding on Rate of Seeding Winter Wheat (illus- 
trated), by Director W. M. Jardine. 

The Practical Application of Farm-Management Principles (illustrated), by 
Mr. H. W. Jefifers. 

The Farmer's Response to Economic Factors, by Prof. W. J. Spillman. 

Intensive Agricultural Practice of China and Japan (illustrated), by Prof. 
Alfred Vivian. 

The Society then adjourned, sine die. 



REPORT OF THE TREASURER. 

From November 9, 1914, to July 31, 1915. 
Receipts. 

Balance on hand, November 9, 1914 $ 360.06 

From the Secretary, C. W. Warburton, per his statements Nos. 1-4 . . 324.45 
Membership fees received : 

For 1913 $ 2.00 

For 1914 106.00 

For 1915 512.00 

Fees for collecting checks .25 620.25 

Receipts from libraries for Journal: 

For Volume 5 ' 2.00 

For Volume 6 6.00 

For Volume 7 74.00 82.00 

Total receipts $1,386.76 



312 JOURNAL OF THE AMERICA:: SOCIETY OF AGRONOMY. 



Disbursements. 

1914 Voucher No. 

Nov. 30. E. B. Thompson Co., rent on stereopticon 58 $ 15.00 

Dec. 2. E. D. Veach, rubber stamp 59 .45 

Dec. 2. Collecting foreign check .15 

Dec. 9. C. W. Warburton, Secretary's expenses 60 7.80 

Dec. 9. Maurice-Joyce Eng. Co., cuts 61 12.98 

Dec. 14. L. M. Thayer, printing 62 18.75 

1915" 

Jan. 23. New Era Ptg. Co., printing Journal, 6-^-5 63 193-95 

Feb. 10. Ky. State Univ. Press, printing 64 5.00 

Feb. 10. Maurice-Joyce Eng. Co., cuts 65 2.00 

Feb. 13. Lexington, Ky., post office, stamps 66 10.00 

Mar. 2. C. W. Warburton, Secretary's expenses 67 34-34 

Mar. 16. L. M. Thayer, printing 68 12.75 

Mar. 16. Maurice-Joyce Eng. Co., cuts 69 2.22 

May 5. Maurice-Joyce Eng. Co., cuts 70 4.60 

May 5. New Era Ptg. Co., printing Journal, 6^ and 71 71 281.59 

June II. Maurice-Joyce Co., cuts 72 i.oo 

June II. New Era Ptg. Co., printing Journal, 72 73 115-35 

July 15. New Era Ptg. Co., printing Journal, 7^ 74 117-64 

July 15. L. M. Thayer, printing 75 10.25 

July 30. C. W. Warburton, Secretary's expenses 76 22.20 

Total disbursements $ 868.02 

Balance July 31, 1915 518.74 

$1,386.76 



George Roberts, 

Treasurer. 

Auditing Committee's Statement. 

We have examined the accounts and vouchers of the Treasurer and found 
them correct as reported. 

E. L. Adams, 
Geo. R. Hyslop, 
Auditing Committee. 

REPORTS OF COMMITTEES. 

The reports of the two special committees, those on audit of accounts and 
on nominations, are found elsewhere. The Auditing Committee's report imme- 
diately follows the report of the Treasurer, while that of the Committee on 
Nominations appears at the proper place in the minutes of the business session. 

The reports of three standing committees, those on soil classification and 
mapping, on agronomic terminology, and on varietal nomenclature, follow the 
report of the Executive Committee. 

REPORT OF THE EXECUTIVE COMMITTEE. 

A meeting of the Executive Committee was called at Washington, D. C, No- 
vember 12, 1914, by President C. E. Thorne. 



AC.RONOMTC AFFATKS. 



On motion, it was ordered that the Secretary act as editor of the Journal 
for 1915, with C. V. Piper and T. L. Lyon as associate editors for crops and 
soils respectively, and that the remainder of the hoard he appointed hy the 
President in consultation with the editor and associate editors. 

On motion, it was decided that the next annual meetinj,' of the Society should 
be held at the same place and on the two days preceding the meetings of the 
Association of American Agricultural Colleges and Experiment Stations. 

On motion, the matter of a referendum vote of the meml)ers on an increase 
of dues, ordered by the previous Executive Committee, was indefinitely post- 
poned, as the present dues were found sufilcient to pay the expenses of the 
Society. 

In December, by a mail vote, the Secretary was authorized to arrange for a 
meeting of the Great Plains section at Mandan, N. Dak., July 14-16, 1915, in 
connection with the meeting of the Great Plains Cooperative Association. 

In February, by a mail vote, the Secretary was authorized to arrange for two 
joint sessions with the Society for the Promotion of Agricultural Science and 
the American Farm Management Association, at the Berkeley meetings of the 
three organizations, August 9 and 10, 191 5. 

REPORT OF COMMITTEE ON SOIL CLASSIFICATION AND 

MAPPING. 

In lieu of a report from this committee, the following letter from the chair- 
man, Dr. George N. Coffey, was read by the Secretary. 

Urbana, III., July i, 191 5. 

Mr. C. W. Warburton, 

U. S. Department of Agriculture, 
Washington, D. C. 

Dear Mr. Warburton : Replying to your letter of June 25, will say that the 
Committee on Soil Classification has not been able to do any further work since 
the meeting in Washington last fall and I do not think that there will be any 
report at the meeting in Berkeley. 

I might say in this connection that it is my personal opinion that the com- 
mittee is entirely too large to secure the best results and I believe that it would 
be better to have a committee of three, or not more than five, members and to 
^ have this committee made up entirely of men who have had actual field expe- 
rience in classifying and mapping soils. If you care to present this as a sug- 
gestion to the Society, which could be acted upon at the annual meeting, you 
can do so. It seems to me that the general committee has accomplished about 
all that a large committee of this nature can hope to accompHsh and that it is 
now time for a few men to take the information collected by this committee 
and spend considerable time going over it and working out the matter more in 
detail. It is absolutely impossible to get a large committee together at any 
other time than the meeting 'of the Society and then there are always so many 
things doing that it is impossible to get down to real work. 

Yours very truly, 
(Signed) George N. Coffey, 

Chairman. 



314 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 

REPORT OF COMMITTEE ON AGRONOMIC TERMINOLOGY. 

For the Committee on Agronomic Terminology I would report that the work 
of card cataloguing new or little-known terms used in agronomic literature has 
been continued during the year. In some instances where such terms have 
seemed especially obscure or unsuited to the use made of them, correspondence 
with the author of the term has brought out the reason for its use and the 
meaning intended. Such correspondence and many personal conferences with 
agronomic workers has shown that there exists a feeling that something on 
the order of a glossary of new or little-known terms in agronomy would be 
helpful. The committee has in mind for the coming winter the compiling and 
publishing in the Journal of tentative lists of such terms, with recommenda- 
tions as to their usage, and in this way submitting them to the consideration 
and judgment of the Society. 

Respectfully submitted, 

For the Committee, 

Carleton R. Ball, 

Chairman. 

REPORT OF THE COMMITTEE ON VARIETAL 
NOMENCLATURE. 

The Committee on Varietal Nomenclature of the American Society of 
Agronomy was appointed by the meeting at Columbus, Ohio, in the fall of 
1911. At that time, the chairman of the committee pointed out the need of 
work along this line as a result of some studies which had been carried on at 
the Nebraska station with some 500 varieties of American oats which had been 
collected from seedsmen and experiment stations. It was stated at that time 
that there was evidently very much confusion in names, as different types of 
oats often had the same name, while the same variety had different names. 

While your committee has not felt that it could directly take up the work 
on this problem, it has nevertheless at each annual meeting submitted a report 
calling attention to the situation and attempting to encourage those engaged in 
research to take up work along this line. Since 191 1 considerable progress has 
been made in nomenclature work, and the committee takes this occasion to 
review the work undertaken or published during the past three years and set 
forth the present status of the case. 

Oats. — In the spring of 1912, the 500 or more samples of oats referred to 
above which had been growing at the Nebraska station for the three years 
previous were turned over to Mr. C. W. Warburton of the U. S. Department 
of Agriculture. He added some new material and the complete collection has 
since been growing at the Nebraska, Iowa, and Cornell University stations, 
while a considerable portion of it has been grown under irrigation in southern 
Idaho. At Cornell Mr. W. C. Etheridge is just now completing three years' 
study of the varieties and is about ready to publish his thesis on classification. 
He has also made a very complete review of similar work that has been done 
in European countries and his work will be of great assistance in clarifying 
the situation. When further observations and studies have been made by 
others interested, we should have the nomenclature of oats pretty clearly 
worked out. 



AGRONOMIC AFFAIRS. 



Barley. — Mr. IT. V. Iliulan of the U. S. Department of Aj^aiciiltiirc has been 
studying the classification of l)arleys for several years and will prcjhahly be 
ready to publish his work on the classification of barleys within \hv. next year. 
There are in the country several good collections of barleys which have been 
studied more or less in cooperation with the U. S. Department of Agriculture. 
The collection at the University of California and a very similar collection 
which during the past two or three years has been grown by the Clemens 
Horst Company of California might be mentioned particularly. These barleys 
together with the collections from several other sources are also now being 
grown in the gardens at Cornell University. Upwards of 600 samples have 
been collected, representing about 300 varieties. 

Wheat. — The first attempt to make a classification of wheat in this country 
was that of Mr. M. A. Carleton, the results of which were pul)lished in Bulletin 
No. 24 of the Division of Vegetable Physiology and Pathology of the U. S. 
Department of Agriculture. Other studies made by men in that Department 
have contributed information from time to time on the types and varieties of 
wheat, especially those of Mr. C. S. Scofield on the classification of durum 
wheat. Within the past year, Messrs. Carleton, Ball and Clark have planned 
to make a thorough study and classification of wheat types and varieties. Re- 
garding this work Mr. Ball writes in a recent letter : 

" We have under way a classification of American wheats which is progress- 
ing rapidly and satisfactorily, considering the size of the job. Some 2,000 to 
3,000 varieties, forms, and strains are in the classification nurseries this season 
at each of three or four different stations, making a total of nearly 10,000 
separate rows this year. These include common, club, poulard, Polish, and 
durum wheats, as also emmer, spelt, and einkorn. 

" They are sown in classification arrangement, using 7 characters which were 
worked out last season. These are, in order, for each group named above, 
beards, glume color, glume covering (pubescence), beak length, kernel color, 
kernel size, and kernel density (hardness). This season we are getting full 
notes on plant and spike characters and this winter in laboratory we will get 
the more minute kernel characters and of course check on the three we used 
last winter. 

" From a field standpoint the work is already yielding some interesting and 
helpful results in the way of proving the identity of many local or little-known 
varieties with standard or widely-known sorts. 

" It is a pleasure to record that the staff of the Office of Grain Standardiza- 
tion, so far as they are concerned with wheat, are intensely interested in the 
problem and are furnishing us with information, samples and assistance which 
are of the greatest possible help in the promotion of the work. 

" The outline of classification prepared last winter comprises 45 typewritten 
pages and it will be enormously expanded by the work of this season." 

The classification of Ohio wheat is being studied by Mr. M. F. Abell at Ohio 
State University with a collection of about 400 varieties. 

Corn. — No serious attempt has been made to classify the varieties of corn 
since Sturtevant's work pubHshed in 1901. However, much new information 
has since appeared about new types and strains of corn in South America and 
the southwestern United States and also from the Old World. There is an 
excellent opportunity for some one to again take up the study and classify 



3l6 JOURNAL OF THE AMERICAN SOCIETY OF AGRONOMY. 



corn, enlarging on Sturtevant's work and also making the classification more 
detailed by using stalk characters as well as ear characters. 

Potatoes— ULr. William Stuart of the U. S. Department of Agriculture has 
been for a number of years making a study of American varieties of potatoes 
and has just published his results in a rather brief form in Department Bulle- 
tin No. 176. This is an admirable piece of work and has done a great deal to 
clarify our knowledge regarding the relationship between our principal varieties 
and groups of potatoes. We shall look to Mr. Stuart for continued effort 
along this line in the future. 

Other Crops. — In making a review of the present status of the nomen- 
clature of American farm crops we should not fail to mention the excellent 
classification work on sorghums by Mr. Carleton R. Ball. His work, with the 
further study by Prof. C. V. Piper, has given us a very excellent idea of the 
types, varieties and relationship of the members of the sorghum family. Pro- 
fessor Piper's excellent work on the classification of cowpeas, soy beans and 
members of the velvet bean group has done much to clarify this difficult 
field. While continued work is needed along all lines which have so far been 
studied in order to complete and perfect these classifications, there is also much 
work needed along the lines where little has so far been done. We are espe- 
cially in need of work in the classification of the economic legumes. The 
excellent classification made some years ago by Mr. C. D, Jarvis and published 
in Cornell University Agr. Expt. Sta. Bui. No. 260 should now be enlarged to 
include a complete classification of American varieties of beans and closely 
related species. There is also excellent opportunity for work with the alfalfas, 
clovers, vetches and many other minor groups. 

How Shall We Make Use of These Classifications? — As this work on the 
classification of varieties goes on more practical use should be made of the 
work. It has been suggested that at least every experiment station in the 
country should keep growing in their gardens a collection of the type varieties 
of all important economic plants. The seed of these type varieties should 
come from some official source in order to know that they are correctly named. 
With type varieties to work from, it would not be difficult to. determine 
whether the common varieties which are being cultivated are properly named 
or not. Seedsmen of the country should also be interested in this matter and 
effort made to see that the commercial varieties that they are putting out are 
properly named. Those connected with the experiment stations and engaged 
in plant breeding who from time to time are putting out new selections should 
observe some simple rules of nomenclature in order not to be giving new 
names to old standard varieties. The committee still believes that the sugges- 
tions made at the last meeting of the Society (Jour. Amer. Soc. Agron., 7: 
29-31, 1915) in regard to having an American registry for varieties something 
on the plan of the herd books which the livestock societies maintain would be 
an excellent scheme and should serve to keep records of names straight in 
the future. 

E. G. Montgomery, 
W. M. Jardtne, 
A. G. McCall, 

Committee. 



INDEX. 



Page. 

Address list of members 298 

Agronomic affairs, 

39, 88, 141, 189, 252, 293 

Agronomic terminology, Report of 

committee on 3^4 

Agronomist, American, Work of 

the 257 

Alfalfa, Effect of different meth- 
ods of inoculation on yield 
and protein content of 172 

American agronomist, Work of 

the 257 

Arny, A. C, and Thatcher, R. W., 
paper on " The effect of 
different methods of inocu- 
lation on the yield and pro- 
tein content of alfalfa and 
sweet clover " 172 

Association meetings 44 

Bacteriological analysis, Soil sam- 
pling for 239 

Books, New 91 

Bort, Katherine S., see Piper, C. V. 

Breaking strength of straw. Meth- 
od for testing the 118 

Brown, P. E., and Johnson, H. 
W., paper on " The effect of 
grinding the soil on its re- 
action as determined by the 

Veitch method " 216 

and Kellogg, E. H., paper on 
" Sulfur and permanent soil 
fertility in Iowa" 97 

Carleton, M. A., paper on " Prob- 
lems of the wheat crop"... 78 

Carrier, Lyman, see Ellett, W. B. 

Chemical composition, Relation of, 

to soil fertility 33 

Clipping, Effect of frequent, on 
yield and composition of 
grasses 85 



Page. 

Coffey, G. N., and Tuttlc, H. 
Foley, paper on " Pot tests 
with fertilizers compared 
with field trials" (Fig. 5).. 129 

Committees, Reports of the 312 

j Agronomic terminology 314 

Executive 3^2 

i Soil classification and map- 

I ping 313 

Varietal nomenclature 314 

Corn, crossing varieties of, Im- 
mediate effect of, on size of 

seed 265 

in Hawaii, The production of 36 
Kernels, Seed values of butt, 

j middle and tip 159 

Crossing varieties of corn, Imme- 
diate effect of 265 

Cumarin and vanillin, Effect of, 
on wheat in soil, sand and 
water cultures 145, 221 

Davidson, Jehiel, paper on " A 
comparative study of the 
effect of cumarin and va- 
nillin on wheat grown in 
soil, sand and water cul- 
tures " 145, 221 

Development of the wheat ker- 
nel. Progressive 273 

Drying of soils. Studies in the... 49 

Dupre, J. v., see Lynde, C. J. 

Ellett, W. B., and Carrier, Lyman, 
paper on " The effect of 
frequent clipping on total 
yield and composition of 
grasses " 85 

Etheridge, W. C, paper on "Va- 
rietal names of oats " i£6 

Events, Coming 49, 95, 192, 256 

Executive committee, Report of 

the 312 

7 



3i8 



INDEX. 



Page. 

Fertilizers, Pot tests with, com- 
pared with field trials 129 

Fraps, G. S., brief article on 
"Moisture relations of 

Texas soils " 31 ! 

brief article on " Relation of 
chemical composition to soil 
fertility " 33 

Funds collected by the secretary.. 295 



by the treasurer 311 

Grain crop mixtures 20 

Grasses, Effect of clipping on yield 

and composition of 85 

Grinding the soil, Effect of, on 
its reaction by the Veitch 
method 216 

Hawaii, Production of corn in . , . 36 
Helmick, B. C., paper on "A 



method for testing the 
breaking strength of straw" 
(Fig. 4, and PI. I, fig. i)... 118 
History of timothy. Early agri- 



cultural I 

Hybrids, Natural wheat-rye 209 

Inoculation, Effect of methods of, 

on alfalfa and sweet clover 172 

Iowa local section 94 

Iowa, Sulfur and permanent soil 

fertility in 97 

Johnson, H. W., see Brown, P. E. 
Journal and Proceedings, Secre- 
tary's report on 308 

Kansas local section, Annual re- 
port of 46 

Kellogg, E. H., see Brown, P. E. 

Kernel, wheat, Progressive devel- 
opment of the 273 

Klein, Millard A., paper on " Stud- 
ies in the drying of soils " 
(Fig. 3) 49 



Lacy, Mary G., paper on " Seed 
values of maize kernels — 
butts, middles and tips"... 159 



Page. 

Leighty, Clyde E., paper on " Nat- 
ural wheat-rye hybrids " . . 209 

Local sections 48, 96, 256, 296 

Love, H. H., paper on " Methods 
of determining weight per 
bushel" (PI. I, fig. 2) 121 

Lynde, C. J., and Dupre, J. V., 
paper on " On osmosis in 

soils" (Fig. I) 15 

paper on " On osmosis in 
soils" (Figs. 14-15) 283 

McCall, A. G., paper on " A new 
method for the study of 
plant nutrients in sand cul- 
tures " (PI. IV, fig. 2) .... 249 

McClelland, C. K., brief article on 
" The production of corn in 
Hawaii " 36 

Maize kernels, seed values of 

butts, middles and tips 169 

Meetings of the society 296, 309 

Methods for determining weight 

per bushel 121 

Members, Address list of 298 

Members, Names of new, 

41, 90, 141, 190, 255, 297 

Membership changes, 

41, 89, 141, 190, 255 

Membership, Secretary's report on 296 

Minutes of the annual meeting... 309 



Mixtures, Grain crop 20 

Moisture relations of Texas soils 31 
Montgomery, E, G., brief article 

on "On naming varieties". 29 
Morse, W. J., note on soy-bean 

inoculation 140 

Naming varieties 29 

Nitrogen, soil, Influence of organic 
materials on transformation 
of 193 

Nomenclature, varietal. Report of 

committee on 314 

Notes and news, 

42, 92, 143, 191, 252, 293 

Noyes, H. A., paper on " Soil sam- 
pling for bacteriological 
analysis" (Fig. 13, and PI. 
IV, fig. I) 239 



INDEX. 



3 '9 



Tagic. 

Nutrients, plant, New niclliod for 

the study of 249 

Oats, Varietal names of 186 

Organic materials. Influence of, 
on transformation of soil 

nitrogen 193 

Osmosis in soils 15, 283 

Piper, Charles V., paper on " The 
prototype of the cultivated 

sorghums " 109 

and Bort, Katherine S., paper 
on " The early agricultural 
history of timothy" i 

Plant nutrients. Method for the 

study of, in sand cultures . . . 249 

Pot tests with fertiHzers compared 

with field trials 129 

Presidential address 257 

Proceedings and Journal, Secre- 
tary's report on 308 

Protein content of alfalfa and 
sweet clover, Effect of in- 
oculation on 172 

Relation of chemical composition 

to soil fertility 33 

Report of the secretary 295 

of the treasurer 311 

Reports of committees 312 

of local sections 44, 95, 144 

Sampling, Soil, for bacteriological 

analysis 239 

Sand .cultures. New method for 
the study of plant nutrients 
in 249 

Secretary, Report of the 295 

Sections, Local 48, 96, 256, 296 

Seed values of maize kernels — 

butts, middles and tips 169 

Soil, Effect of grinding the, on its 
reaction by the Veitch 

method ' 216 

classification and mapping, 
Report of committee on . . . 313 

Soil fertility. Sulfur and perma- 
nent, in Iowa 97 



Page. 

Relation of chemical compo- 
sition to 33 

Soil nitrogen, Influence of organic 
materials on the transfor- 
mation of 193 

Soil osmosis 15, 283 

Soil sampling for bacteriological 

analysis 239 

Soils, Moisture relations of Texas 31 
Studies in the drying of 49 

Sorghums, Prototype of the culti- 
vated 109 

Soy bean inoculation. Variations 

in 139 

Straw, breaking strength of. 

Method for testing the 118 

Sulfur and permanent soil fer- 
tility in Iowa 97 

Sweet clover. Effect of different 
methods of inoculation on 
yield and protein content of 172 

Terminology, agronomic. Report 

of committee on 314 

Texas soils. Moisture relations of 31 

Thatcher, R. W., paper on " Pro- 
gressive development of the 
wheat kernel — II " 273 

Thorne, Charles E., paper on "The 
work of the American 
agronomist" (presidential 
address) 257 

Timothy, The early agricultural 

history of I 

Treasurer, Report of the 311 

Tuttle, H. Foley, see Coffey, G. N. 

Vanillin and cumarin, Effect of, 
on wheat in soil, sand and 
water cultures 145, 221 

Varietal names. The problem of.. 40 
of oats 186 

Varieties, Naming 29 

Veitch method, Effect of grinding 
the soil on its reaction as 
determined by 216 

Voorhees, John H., paper on 
** Variation in soy bean 
inoculation " 139 



INDEX. 



320 

Page. 

Warburton, C. W., paper on 
" Grain crop mixtures " 
(Fig. 2) 20 

Washington, D. C, local section, 

46, 95, 144 

Weight per bushel, Methods for \ 
determining 121 

Wheat, Effect of cumarin and 

vanillin on 145, 221 

Wheat crop, Problems of the ... 78 

Wheat kernel. Progressive devel- 
opment of the 273 

Wheat-rye hybrids, Natural 209 



Page. 

Wolfe, T. K., paper on "Further 
evidence of the immediate 
effect of crossing varieties 
of corn on the size of seed 

produced " 265 

j Wright, R. Claude, paper on " The 
influence of certain organic 
materials upon the trans- 
formation of soil nitrogen 
(Figs. 6-12) 193 

Yield of alfalfa and sweet clover, 

Effect of inoculation on . . . 172 



VOLUME 7 



NUMBER 



JOURNAL 

OF THE 

American Society of Agronomy 



NOVEMBER-DECEMBER, 1915 



CONTENTS 



The Work of the Agaerican Agronomist. (Presidential Address.) Charles E. 

Thorne 257 

Further Evidence of the Immediate Effect of Crossing Varieties of Corn on 

the Size of the Seed Produced. T. K. Wolfe 265 

The Progressive Development of the Wheat Kernel — II. R. W. Thatcher. . . . 273 

On Osmosis in Soils (Figs. 14-15). C. J. Lynde and J. V. Dupre 283 

Agronomic Affairs. 

Notes and News 293 

Report of the Secretary for 1915 (Funds Collected, — Meetings, — Local Sec- 
tions, — Membership, — Address List of Members, — Journal and Proceedings, 

Minutes of the Annual Meeting) 295 

Report of the Treasurer 311 

Reports of Committees (Executive, — Soil Classification and Mapping, — 

Agronomic Terminology, — Varietal Nomenclature) 312 

Index 317 



PUBLISHED BY THE SOCIETY 

WASHINGTON, D. C. 

PReSS OF 
THE NEW ERA PRINTING COMPANr 
LANCASTER, PA. 

Issued December "I, igi5 



Entered as second class matter March 27, 1914, at the post office at Washington, D, C, 
under the Act of August 24, igi2. 



JOURNAL 



OF THE 

American Society of Agronomy 

A Bimonthly Journal of Agronomy 



Editor 
C. W. WARBURTON 

Associate Editors 
Crops: CHARLES V. PIPER 
Soils: T. LYTTLETON LYON 

Assistant Editors 

Crop Production, C. A. ZAVITZ Soil Physics, L. E. CALL 

Crop Breeding, L. H. SMITH Soil Chemistry, W. P. KELLEY 

Crop Chemistry, R. W. THATCHER Soil Biology, J. G. LIPMAN 



MANUSCRIPTS 

Suitable articles concerned with instruction, demonstration, experimentation or 
research in agronomy will be accepted for publication. Papers of any length, between 
I page and 30 or 40 pages, can be used. Personal and institutional items of agro- 
nomic interest, suitable for inclusion in "Notes and News," are solicited. 

■ To be accepted for publication, manuscripts should be original typewritten copies 
(not carbons) double- or triple-spaced, with wide margins. Special care should be 
gnven to the proper indication of main heads and subheads in the text, to preparation 
and descriptions of tables, to citations of literature and to illustrations. For fuller 
details see recommendations on page 28 of volume 3 of Proceedings and examples in 
that and other volumes. 

All illustrations desired should accompany the manuscript, should be numbered 
and described, and referred to in the text. Line drawings must be made in India ink- 
and glossy velox prints of photographs are preferred for half-tones. 

REPRINTS 

Reprints may be purchased at the prices quoted below. Orders should be sent 
to the Editor immediately on receipt of proof of article. 

Copies 2 pp. 4 pp. 8 pp. 12 pp. 16 pp. 20 pp. 24 pp. 28 pp. 32 pp. 

50 $1.27 $1.37 $1.87 $2.12 $2.50 $3.50 $4.05 $4-82 $5.20 

75 I-3I 1.46 2.00 2.38 2.82 3.75 4-50 5.46 5.85 

100 1.35 I.S5 2.15 2.65 3-15 405 5.00 6.10 6.50 

200 1.60 2.00 3.05 4.00 4.30 5.60 6.90 8.30 8.90 

Covers on same paper as the publication with printed title page, 50 covers $1.00, 
and I cent for each additional copy. Plates 40 cents per 100 or fraction thereof, 
including insertion. 



THE AMERICAN SOCIETY OF AGRONOMY 



OBJECT 

Article II. The object of the Society shall be the increase and dissemination of 
knowledge concerning soils and crops and the conditions affecting them. 

MEMBERSHIP 

Article IV. Membership shall be of three kinds, active, associate and local. 
Active membership shall be limited to persons who are engaged in teaching agronomy 
or in scientific investigation in some branch of agronomy. Associate membership shall 
be composed of other persons interested in the object of the Society. Associate mem- 
bers shall be entitled to all the privileges of the Society except that of voting. Local 
members shall have no vote in the Society and shall not be entited to a copy of the 
printed proceedings without payment of an extra sum of money as provided in Article 
V of this Constitution. 

Active and associate membership may be secured by the endorsement in writmg 
of some active member and upon approval by the President and Secretary and pay- 
ment of the annual dues. 

Members who take up residence outside of North America may retain their mem- 
bership on the same terms as members living in America. 

BY-LAWS 

1. The annual dues for each active and associate member shall be $2, and for each 
local member $.50, which shall be paid on or before April i of the year for which 
membership is held. 

2. Any member in arrears for dues for more than one year shall thereby forfeit 
membership, but may be restored to membership without action of the Society upon 
the payment of such arrears. 

Applications for membership should be sent to the Secretary, preferably accom- 
panied by remittance for dues, to save correspondence. Except when accompanying 
applications for membership, all dues should be paid to the Treasurer. 

PUBLICATIONS 

Proceedings. Four volumes of Proceedings have been issued, as follows : 

Vol. I, cloth, 238 pp., 39 papers, 1909.. Price $2.00, post paid. 

Vol. 2, cloth, 154 pp., 16 papers, 1910. Price $2.00, post paid. 

Vol. 3, cloth, 286 pp., 14 papers, 191 1. Price $2.00, post paid. 

Vol. 4, cloth, 160 pp., 20 papers, 1912. Price $2.00, post paid. 

Journal (continuing the Proceedings). 

Vol. 5, quarterly, paper, 256 pp., 1913. Price $2.00, post paid. Single copies, 
64 pp., 60 cents each, post paid. 

Vol. 6, 1914, and Vol. 7, 1915, bimonthly, paper. Price $2.00 each, post paid. SingU 
copies, 48 pp., 35 cents each, post paid. 

Libraries and individuals are invited to place subscriptions for the current volume 
and orders for previous volumes with the Secretary, C. W. Warburton, U. S. Depart- 
ment of Agriculture, Washington, D. C. 

Special reduced price to members for volumes i to 6, inclusive. 



AMERICAN SOCIETY OF AGRONOMY 



OFFICERS 

President 

First Vice-President 

Second Vice-President 

Secretary 

Treasurer 

COMMITTEES 

EXECUTIVE COMMITEE 

COMPOSFD OF THE OFFICERS OF THE SoCIETY 

COMMITTEE ON SOIL CLASSIFICATION AND MAPPING 
Members, 1913-1915 

G. N. Coffey, chairman; F. T. Shutt, C. E. Thorne, 

H. J. Wheeler, A. R. Whitson. 

Members, 1914-1916 

E. O. Fippin, G. S. Fraps. A. J. Galbraith, 

Alvin Keyser, B. W. Kilgore. 

Members, 1915-1917 

F. J. Alway, R. H. Loughridge, C. F. Marbut, 

C A. Mooers, J. G. Mosier. 

COMMITTEE ON STANDARDIZATION OF FIELD EXPERIMENTS 
C. V. Piper, chairman; E. G. Montgomery, W. H. Stevenson. 

COMMITTEE ON TERMINOLOGY 
Carleton R, Ball, chairman; C. G. Hopkins, J. F. Duggar. 



C. E. Thorne 
,L. J. Briggs 
Alfred Atkinson 
C. W. Warburton 
George Roberts 



COMMITTEE ON VARIETAL NOMENCLATURE 
E. G. Montgomery, chairman; A. G. McCall, W. M. Jardine.